--
-- E-Maj extension: upgrade from 1.3.1 to 2.0.0
--
-- This software is distributed under the GNU General Public License.
--
-- This script upgrades an existing installation of E-Maj extension.
--

-- complain if this script is executed in psql, rather than via an ALTER EXTENSION statement
\echo Use "ALTER EXTENSION emaj UPDATE TO..." to upgrade the E-Maj extension. \quit

--SET client_min_messages TO WARNING;
SET client_min_messages TO NOTICE;

------------------------------------
--                                --
-- checks                         --
--                                --
------------------------------------
-- Check that the upgrade conditions are met.
DO
$do$
  DECLARE
    v_emajVersion            TEXT;
    v_groupList              TEXT;
  BEGIN
-- check the current role is a superuser
    PERFORM 0 FROM pg_roles WHERE rolname = current_user AND rolsuper;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'E-Maj upgrade: the current user (%) is not a superuser.', current_user;
    END IF;
-- the emaj version registered in emaj_param must be '1.3.1'
    SELECT param_value_text INTO v_emajVersion FROM emaj.emaj_param WHERE param_key = 'emaj_version';
    IF v_emajVersion <> '1.3.1' THEN
      RAISE EXCEPTION 'E-Maj upgrade: the current E-Maj version (%) is not 1.3.1',v_emajVersion;
    END IF;
-- the installed postgres version must be at least 9.1
    IF current_setting('server_version_num')::int < 90100 THEN
      RAISE EXCEPTION 'E-Maj upgrade: the current PostgreSQL version (%) is not compatible with E-Maj 2.0.0. The PostgreSQL version should be at least 9.1.', current_setting('server_version');
    END IF;
-- no existing group must have been created with a postgres version prior 8.4
    SELECT string_agg(group_name, ', ') INTO v_groupList FROM emaj.emaj_group
      WHERE cast(to_number(substring(group_pg_version FROM E'^(\\d+)'),'99') * 100 +
                 to_number(substring(group_pg_version FROM E'^\\d+\\.(\\d+)'),'99') AS INTEGER) < 804;
    IF v_groupList IS NOT NULL THEN
      RAISE EXCEPTION 'E-Maj upgrade: groups "%" have been created with a too old postgres version (< 8.4). Drop these groups before upgrading. ',v_groupList;
    END IF;
  END;
$do$;

-- OK, the upgrade operation can start...

-- lock emaj_group table to avoid any concurrent E-Maj activity
LOCK TABLE emaj.emaj_group IN EXCLUSIVE MODE;

DO
$do$
  DECLARE
  BEGIN
-- if tspemaj tablespace exists, use it as default_tablespace for emaj tables creation
--   and grant the create rights on it to emaj_adm
    PERFORM 0 FROM pg_tablespace WHERE spcname = 'tspemaj';
    IF FOUND THEN
      SET default_tablespace TO tspemaj;
      GRANT CREATE ON TABLESPACE tspemaj TO emaj_adm;
    END IF;
  END;
$do$;

---------------------------------------
--                                   --
-- emaj tables, views and sequences  --
--                                   --
---------------------------------------
--
-- create the new emaj_time_stamp table and populate it
--
-- table containing the time stamps of major E-Maj events.
-- these stamps, used as time references in other internal tables, are insensitive to system time fluctuations and transaction wrapaound.
CREATE TABLE emaj.emaj_time_stamp (
  time_id                      BIGSERIAL   NOT NULL,       -- internal id
  time_clock_timestamp         TIMESTAMPTZ NOT NULL        -- insertion clock time
                               DEFAULT clock_timestamp(),
  time_stmt_timestamp          TIMESTAMPTZ NOT NULL        -- insertion statement start time
                               DEFAULT statement_timestamp(),
  time_tx_timestamp            TIMESTAMPTZ NOT NULL        -- insertion transaction start time
                               DEFAULT transaction_timestamp(),
  time_tx_id                   BIGINT                      -- id of the tx that has generated the time stamp
                               DEFAULT txid_current(),
  time_last_emaj_gid           BIGINT,                     -- last value of the E-Maj global sequence
  time_event                   CHAR(1),                    -- event type that has generated the time stamp
                                                           --   C(reate), A(lter), D(rop) , M(ark), R(ollback)
  PRIMARY KEY (time_id)
  );
COMMENT ON TABLE emaj.emaj_time_stamp IS
$$Contains the time stamps of major E-Maj events.$$;

-- create a temporary table with the different time stamp to record
CREATE TEMP TABLE emaj_temp_time_stamp (
  tmp_ts                      TIMESTAMPTZ,
  tmp_event                   CHAR(1)
  );

-- get all known timestamp from groups, marks and rollbacks
INSERT INTO emaj_temp_time_stamp
  SELECT group_creation_datetime, 'C' FROM emaj.emaj_group;
INSERT INTO emaj_temp_time_stamp
  SELECT group_last_alter_datetime, 'A' FROM emaj.emaj_group WHERE group_last_alter_datetime IS NOT NULL;
INSERT INTO emaj_temp_time_stamp
  SELECT mark_datetime, 'M' FROM emaj.emaj_mark;
INSERT INTO emaj_temp_time_stamp
  SELECT rlbk_start_datetime, 'R' FROM emaj.emaj_rlbk;

-- build the emaj_time_stamp table
INSERT INTO emaj.emaj_time_stamp (time_clock_timestamp, time_stmt_timestamp, time_tx_timestamp, time_tx_id, time_event)
  SELECT DISTINCT ON (tmp_ts, tmp_event) tmp_ts, tmp_ts, tmp_ts, NULL, tmp_event
    FROM emaj_temp_time_stamp
    ORDER BY tmp_ts, tmp_event;
-- copy the known global sequence value for each mark
UPDATE emaj.emaj_time_stamp SET time_last_emaj_gid = mark_global_seq
  FROM emaj.emaj_mark
  WHERE mark_datetime = time_clock_timestamp;

-- and finaly drop the temporary table
DROP TABLE emaj_temp_time_stamp;

--
-- process the emaj_group table
--
-- create a temporary table with the old structure and copy the source content
CREATE TEMP TABLE emaj_group_old (LIKE emaj.emaj_group);

INSERT INTO emaj_group_old SELECT * FROM emaj.emaj_group;

-- drop the old table
DROP TABLE emaj.emaj_group CASCADE;

-- create the new table, with its indexes, comment, constraints (except foreign key)...
CREATE TABLE emaj.emaj_group (
  group_name                   TEXT        NOT NULL,
  group_is_logging             BOOLEAN     NOT NULL,       -- are log triggers activated ?
                                                           -- true between emaj_start_group(s) and emaj_stop_group(s)
                                                           -- false in other cases
  group_is_rlbk_protected      BOOLEAN     NOT NULL,       -- is the group currently protected against rollback ?
                                                           -- always true for AUDIT_ONLY groups
  group_nb_table               INT,                        -- number of tables at emaj_create_group time
  group_nb_sequence            INT,                        -- number of sequences at emaj_create_group time
  group_is_rollbackable        BOOLEAN     NOT NULL,       -- false for 'AUDIT_ONLY' and true for 'ROLLBACKABLE' groups
  group_creation_time_id       BIGINT      NOT NULL,       -- time stamp of the group's creation
  group_last_alter_time_id     BIGINT,                     -- time stamp of the last emaj_alter_group() call
                                                           -- set to NULL at emaj_create_group() time
  group_pg_version             TEXT        NOT NULL        -- postgres version at emaj_create_group() time
                               DEFAULT substring (version() from E'PostgreSQL\\s([.,0-9,A-Z,a-z]*)'),
  group_comment                TEXT,                       -- optional user comment
  PRIMARY KEY (group_name),
  FOREIGN KEY (group_creation_time_id) REFERENCES emaj.emaj_time_stamp (time_id),
  FOREIGN KEY (group_last_alter_time_id) REFERENCES emaj.emaj_time_stamp (time_id)
  );
COMMENT ON TABLE emaj.emaj_group IS
$$Contains created E-Maj groups.$$;

-- populate the new table
INSERT INTO emaj.emaj_group (
  group_name, group_is_logging, group_is_rlbk_protected, group_nb_table, group_nb_sequence, group_is_rollbackable, 
  group_creation_time_id, group_last_alter_time_id, group_pg_version, group_comment)
  SELECT group_name, group_is_logging, group_is_rlbk_protected, group_nb_table, group_nb_sequence, group_is_rollbackable, 
  ts1.time_id, ts2.time_id, group_pg_version, group_comment
    FROM emaj_group_old
         JOIN emaj.emaj_time_stamp ts1 ON group_creation_datetime = ts1.time_tx_timestamp AND ts1.time_event = 'C'
         LEFT OUTER JOIN emaj.emaj_time_stamp ts2 ON group_last_alter_datetime = ts2.time_tx_timestamp AND ts1.time_event = 'A';

-- recreate the foreign keys that point on this table
ALTER TABLE emaj.emaj_relation ADD FOREIGN KEY (rel_group) REFERENCES emaj.emaj_group (group_name) ON DELETE CASCADE;
ALTER TABLE emaj.emaj_mark ADD FOREIGN KEY (mark_group) REFERENCES emaj.emaj_group (group_name) ON DELETE CASCADE;

--
-- process the emaj_mark table
--
-- create a temporary table with the old structure and copy the source content
CREATE TEMP TABLE emaj_mark_old (LIKE emaj.emaj_mark);

INSERT INTO emaj_mark_old SELECT * FROM emaj.emaj_mark;

-- drop the old table
ALTER EXTENSION emaj DROP SEQUENCE emaj.emaj_mark_mark_id_seq;
DROP TABLE emaj.emaj_mark CASCADE;

-- create the new table, with its indexes, comment, constraints (except foreign key)...
CREATE TABLE emaj.emaj_mark (
  mark_group                   TEXT        NOT NULL,       -- group for which the mark has been set
  mark_name                    TEXT        NOT NULL,       -- mark name
  mark_id                      BIGSERIAL   NOT NULL,       -- serial id used to order rows (not to rely on timestamps
                                                           -- that are not safe if system time changes)
  mark_time_id                 BIGINT      NOT NULL,       -- time stamp of the mark creation, used as a reference
                                                           --   for other tables like emaj_sequence and all log tables
  mark_is_deleted              BOOLEAN     NOT NULL,       -- boolean to indicate if the mark is deleted
  mark_is_rlbk_protected       BOOLEAN     NOT NULL,       -- boolean to indicate if the mark is protected from rollbacks (false by default)
  mark_comment                 TEXT,                       -- optional user comment
  mark_log_rows_before_next    BIGINT,                     -- number of log rows recorded for the group between the mark
                                                           -- and the next one (NULL if last mark)
                                                           -- used to speedup marks list display in phpPgAdmin plugin
  mark_logged_rlbk_target_mark TEXT,                       -- for marks generated by logged_rollback functions, name of the rollback target mark
  PRIMARY KEY (mark_group, mark_name),
  FOREIGN KEY (mark_group) REFERENCES emaj.emaj_group (group_name) ON DELETE CASCADE,
  FOREIGN KEY (mark_time_id) REFERENCES emaj.emaj_time_stamp (time_id)
  );
COMMENT ON TABLE emaj.emaj_mark IS
$$Contains marks set on E-Maj tables groups.$$;

-- populate the new table
INSERT INTO emaj.emaj_mark (
         mark_group, mark_name, mark_id, mark_time_id, mark_is_deleted, mark_is_rlbk_protected,
         mark_comment, mark_log_rows_before_next)
  SELECT mark_group, mark_name, mark_id, time_id, mark_is_deleted, mark_is_rlbk_protected,
         mark_comment, mark_log_rows_before_next
    FROM emaj_mark_old, emaj.emaj_time_stamp
    WHERE mark_datetime = time_clock_timestamp AND time_event = 'M';

-- recreate the foreign keys that point on this table
-- na

-- set the last value for the sequence associated to the serial column
SELECT CASE WHEN EXISTS (SELECT 1 FROM emaj.emaj_mark) 
              THEN setval('emaj.emaj_mark_mark_id_seq', (SELECT max(mark_id) FROM emaj.emaj_mark))
       END;

--
-- process the emaj_sequence table
--
-- create a temporary table with the old structure and copy the source content
CREATE TEMP TABLE emaj_sequence_old (LIKE emaj.emaj_sequence);

INSERT INTO emaj_sequence_old SELECT * FROM emaj.emaj_sequence;

-- drop the old table
ALTER EXTENSION emaj DROP SEQUENCE emaj.emaj_sequence_sequ_id_seq;
DROP TABLE emaj.emaj_sequence CASCADE;

-- create the new table, with its indexes, comment, constraints (except foreign key)...
CREATE TABLE emaj.emaj_sequence (
  sequ_schema                  TEXT        NOT NULL,       -- application or 'emaj' schema that owns the sequence
  sequ_name                    TEXT        NOT NULL,       -- application or emaj sequence name
  sequ_time_id                 BIGINT      NOT NULL,       -- time stamp when the sequence characteristics have been recorded
                                                           --   the same time stamp id as referenced in emaj_mark table
  sequ_last_val                BIGINT      NOT NULL,       -- sequence last value
  sequ_start_val               BIGINT      NOT NULL,       -- sequence start value
  sequ_increment               BIGINT      NOT NULL,       -- sequence increment
  sequ_max_val                 BIGINT      NOT NULL,       -- sequence max value
  sequ_min_val                 BIGINT      NOT NULL,       -- sequence min value
  sequ_cache_val               BIGINT      NOT NULL,       -- sequence cache value
  sequ_is_cycled               BOOLEAN     NOT NULL,       -- sequence flag 'is cycled ?'
  sequ_is_called               BOOLEAN     NOT NULL,       -- sequence flag 'is called ?'
  PRIMARY KEY (sequ_schema, sequ_name, sequ_time_id),
  FOREIGN KEY (sequ_time_id) REFERENCES emaj.emaj_time_stamp (time_id)
  );
COMMENT ON TABLE emaj.emaj_sequence IS
$$Contains values of sequences at E-Maj set_mark times.$$;

-- populate the new table
INSERT INTO emaj.emaj_sequence (
         sequ_schema, sequ_name, sequ_time_id, sequ_last_val, sequ_start_val, 
         sequ_increment, sequ_max_val, sequ_min_val, sequ_cache_val, sequ_is_cycled, sequ_is_called)
  SELECT sequ_schema, sequ_name, time_id, sequ_last_val, sequ_start_val,
         sequ_increment, sequ_max_val, sequ_min_val, sequ_cache_val, sequ_is_cycled, sequ_is_called
    FROM emaj_sequence_old, emaj.emaj_time_stamp
    WHERE sequ_datetime = time_clock_timestamp AND time_event = 'M';

-- recreate the foreign keys that point on this table
-- na

-- set the last value for the sequence associated to the serial column
-- na

--
-- process the emaj_seq_hole table
--
-- create a temporary table with the old structure and copy the source content
CREATE TEMP TABLE emaj_seq_hole_old (LIKE emaj.emaj_seq_hole);

INSERT INTO emaj_seq_hole_old SELECT * FROM emaj.emaj_seq_hole;

-- drop the old table
ALTER EXTENSION emaj DROP SEQUENCE emaj.emaj_seq_hole_sqhl_id_seq;
DROP TABLE emaj.emaj_seq_hole;

-- create the new table, with its indexes, comment, constraints (except foreign key)...
CREATE TABLE emaj.emaj_seq_hole (
  sqhl_schema                  TEXT        NOT NULL,       -- schema that owns the application table
  sqhl_table                   TEXT        NOT NULL,       -- application table for which a sequence hole is recorded in the associated log table
  sqhl_begin_time_id           BIGINT      NOT NULL,       -- time stamp id of the lower range limit of the hole
  sqhl_end_time_id             BIGINT      NOT NULL,       -- time stamp id of the upper range limit of the hole
  sqhl_hole_size               BIGINT      NOT NULL,       -- hole size computed as the difference of 2 sequence last-values
  PRIMARY KEY (sqhl_schema, sqhl_table, sqhl_begin_time_id),
  FOREIGN KEY (sqhl_begin_time_id) REFERENCES emaj.emaj_time_stamp (time_id),
  FOREIGN KEY (sqhl_end_time_id) REFERENCES emaj.emaj_time_stamp (time_id)
  );
COMMENT ON TABLE emaj.emaj_seq_hole IS
$$Contains description of holes in sequence values for E-Maj log tables.$$;

-- populate the new table

-- The emaj_seq_hole structure change needs a quite complex processing.
-- the emaj_mark table must have been upgraded, but the temporary table with its old content must still exist.
DO
$do$
  DECLARE
    v_beginTimeId            BIGINT;
    v_endTimeId              BIGINT;
    v_lastTimeId             BIGINT;
    r_seq_hole               RECORD;
  BEGIN
-- get the last recorded time stamp id.
--   it will be used as end time stamp id for the specific case when a hole is produced by a rollback operation that is not followed by any mark.
    SELECT max(time_id) INTO v_lastTimeId FROM emaj.emaj_time_stamp;
-- for each existing row in the emaj_seq_hole table
    FOR r_seq_hole IN
      SELECT sqhl_id, sqhl_schema, sqhl_table, sqhl_hole_size FROM emaj_seq_hole_old ORDER BY sqhl_id
      LOOP
-- get the id of the target mark of the rollback operation that produced the hole
      SELECT max(emaj_mark.mark_time_id) INTO v_beginTimeId FROM emaj_mark_old, emaj.emaj_mark
        WHERE emaj_mark_old.mark_id = emaj_mark.mark_id
          AND emaj_mark_old.mark_last_seq_hole_id < r_seq_hole.sqhl_id;
-- get the id of the first mark set after the rollback operation that produced the hole
      SELECT coalesce(min(emaj_mark.mark_time_id),v_lastTimeId) INTO v_endTimeId FROM emaj_mark_old, emaj.emaj_mark
        WHERE emaj_mark_old.mark_id = emaj_mark.mark_id
          AND emaj_mark_old.mark_last_seq_hole_id >= r_seq_hole.sqhl_id;
-- insert the new row in the emaj_seq_hole table
      INSERT INTO emaj.emaj_seq_hole (sqhl_schema, sqhl_table, sqhl_begin_time_id, sqhl_end_time_id, sqhl_hole_size)
        VALUES (r_seq_hole.sqhl_schema, r_seq_hole.sqhl_table, v_beginTimeId, v_endTimeId, r_seq_hole.sqhl_hole_size);
    END LOOP;
  END;
$do$;

--
-- process the emaj_rlbk table
--
-- create a temporary table with the old structure and copy the source content
CREATE TEMP TABLE emaj_rlbk_old (LIKE emaj.emaj_rlbk);

INSERT INTO emaj_rlbk_old SELECT * FROM emaj.emaj_rlbk;

-- drop the old table
ALTER EXTENSION emaj DROP SEQUENCE emaj.emaj_rlbk_rlbk_id_seq;
DROP TABLE emaj.emaj_rlbk CASCADE;

-- create the new table, with its indexes, comment, constraints (except foreign key)...
CREATE TABLE emaj.emaj_rlbk (
  rlbk_id                      SERIAL      NOT NULL,       -- rollback id
  rlbk_groups                  TEXT[]      NOT NULL,       -- groups array to rollback
  rlbk_mark                    TEXT        NOT NULL,       -- mark to rollback to
  rlbk_mark_time_id            BIGINT      NOT NULL,       -- time stamp id of the mark to rollback to
  rlbk_time_id                 BIGINT,                     -- time stamp id at the rollback start
  rlbk_is_logged               BOOLEAN     NOT NULL,       -- rollback type: true = logged rollback
  rlbk_nb_session              INT         NOT NULL,       -- number of requested rollback sessions
  rlbk_nb_table                INT,                        -- total number of tables in groups
  rlbk_nb_sequence             INT,                        -- number of sequences to rollback
  rlbk_eff_nb_table            INT,                        -- number of tables with rows to rollback
  rlbk_status                  emaj._rlbk_status_enum,     -- rollback status
  rlbk_begin_hist_id           BIGINT,                     -- hist_id of the rollback BEGIN event in the emaj_hist
                                                           --   used to know if the rollback has been committed or not
  rlbk_is_dblink_used          BOOLEAN,                    -- boolean indicating whether dblink connection are used
  rlbk_end_datetime            TIMESTAMPTZ,                -- clock time the rollback has been completed,
                                                           --   NULL if rollback is in progress or aborted
  rlbk_msg                     TEXT,                       -- result message
  PRIMARY KEY (rlbk_id),
  FOREIGN KEY (rlbk_time_id) REFERENCES emaj.emaj_time_stamp (time_id),
  FOREIGN KEY (rlbk_mark_time_id) REFERENCES emaj.emaj_time_stamp (time_id)
  );
COMMENT ON TABLE emaj.emaj_rlbk IS
$$Contains description of rollback events.$$;

-- populate the new table
INSERT INTO emaj.emaj_rlbk (
         rlbk_id, rlbk_groups, rlbk_mark, rlbk_mark_time_id, rlbk_time_id, rlbk_is_logged,
         rlbk_nb_session, rlbk_nb_table, rlbk_nb_sequence, rlbk_eff_nb_table, rlbk_status, 
         rlbk_begin_hist_id, rlbk_is_dblink_used, rlbk_end_datetime, rlbk_msg)
  SELECT rlbk_id, rlbk_groups, rlbk_mark, t1.time_id, t2.time_id, rlbk_is_logged,
         rlbk_nb_session, rlbk_nb_table, rlbk_nb_sequence, rlbk_eff_nb_table, rlbk_status, 
         rlbk_begin_hist_id, rlbk_is_dblink_used, rlbk_end_datetime, rlbk_msg
    FROM emaj_rlbk_old, emaj.emaj_time_stamp t1, emaj.emaj_time_stamp t2
    WHERE rlbk_mark_datetime = t1.time_clock_timestamp AND t1.time_event = 'M'
      AND rlbk_start_datetime = t2.time_clock_timestamp AND t2.time_event = 'R';

-- create indexes
-- partial index on emaj_rlbk targeting in progress rollbacks (not yet committed or marked as aborted)
CREATE INDEX emaj_rlbk_idx1 ON emaj.emaj_rlbk (rlbk_status)
    WHERE rlbk_status IN ('PLANNING', 'LOCKING', 'EXECUTING', 'COMPLETED');

-- recreate the foreign keys that point on this table
ALTER TABLE emaj.emaj_rlbk_session ADD FOREIGN KEY (rlbs_rlbk_id) REFERENCES emaj.emaj_rlbk (rlbk_id);
ALTER TABLE emaj.emaj_rlbk_plan ADD FOREIGN KEY (rlbp_rlbk_id) REFERENCES emaj.emaj_rlbk (rlbk_id);
ALTER TABLE emaj.emaj_rlbk_stat ADD FOREIGN KEY (rlbt_rlbk_id) REFERENCES emaj.emaj_rlbk (rlbk_id);

-- set the last value for the sequence associated to the serial column
SELECT CASE WHEN EXISTS (SELECT 1 FROM emaj.emaj_rlbk)
              THEN setval('emaj.emaj_rlbk_rlbk_id_seq', (SELECT max(rlbk_id) FROM emaj.emaj_rlbk))
       END;

--
-- process the emaj_rlbk_stat table
--
-- create a temporary table with the old structure and copy the source content
CREATE TEMP TABLE emaj_rlbk_stat_old (LIKE emaj.emaj_rlbk_stat);

INSERT INTO emaj_rlbk_stat_old SELECT * FROM emaj.emaj_rlbk_stat;

-- drop the old table
DROP TABLE emaj.emaj_rlbk_stat;

-- create the new table, with its indexes, comment, constraints (except foreign key)...
CREATE TABLE emaj.emaj_rlbk_stat (
  rlbt_step                    emaj._rlbk_step_enum
                                           NOT NULL,       -- kind of elementary step in the rollback processing
  rlbt_schema                  TEXT        NOT NULL,       -- schema object of the step
  rlbt_table                   TEXT        NOT NULL,       -- table name
  rlbt_fkey                    TEXT        NOT NULL,       -- foreign key name for step on foreign key, or ''
  rlbt_rlbk_id                 INT         NOT NULL,       -- rollback id
  rlbt_quantity                BIGINT      NOT NULL,       -- depending on the step, either estimated quantity processed
                                                           --   by the elementary step or number of executed steps
  rlbt_duration                INTERVAL    NOT NULL,       -- duration or sum of durations of the elementary step(s)
  PRIMARY KEY (rlbt_step, rlbt_schema, rlbt_table, rlbt_fkey, rlbt_rlbk_id),
  FOREIGN KEY (rlbt_rlbk_id) REFERENCES emaj.emaj_rlbk (rlbk_id)
  );
COMMENT ON TABLE emaj.emaj_rlbk_stat IS
$$Contains statistics about previous E-Maj rollback durations.$$;

-- populate the new table
-- only keep the statistics related to not deleted rows from the emaj_rlbk reference table in order to satisfy the new foreign key 
INSERT INTO emaj.emaj_rlbk_stat 
  SELECT rlbt_step, rlbt_schema, rlbt_table, rlbt_fkey, rlbt_rlbk_id, rlbt_quantity, rlbt_duration
    FROM emaj_rlbk_stat_old, emaj.emaj_rlbk
    WHERE rlbt_rlbk_id = rlbk_id;

--
-- Check the number of rows in old and new tables and drop old versions of tables
--
DO
$do$
  DECLARE
    v_nbRowsOld       INT;
    v_nbRowsNew       INT;
  BEGIN
    SELECT count(*) INTO v_nbRowsOld FROM emaj_group_old;
    SELECT count(*) INTO v_nbRowsNew FROM emaj.emaj_group;
    IF v_nbRowsOld <> v_nbRowsNew THEN
      RAISE EXCEPTION 'E-Maj upgrade: internal error, the number of rows in the original emaj_group table (%) doesn''t match the number of rows in the new emaj_group table (%)',v_nbRowsOld, v_nbRowsNew;
    END IF;
    SELECT count(*) INTO v_nbRowsOld FROM emaj_mark_old;
    SELECT count(*) INTO v_nbRowsNew FROM emaj.emaj_mark;
    IF v_nbRowsOld <> v_nbRowsNew THEN
      RAISE EXCEPTION 'E-Maj upgrade: internal error, the number of rows in the original emaj_mark table (%) doesn''t match the number of rows in the new emaj_mark table (%)',v_nbRowsOld, v_nbRowsNew;
    END IF;
    SELECT count(*) INTO v_nbRowsOld FROM emaj_sequence_old;
    SELECT count(*) INTO v_nbRowsNew FROM emaj.emaj_sequence;
    IF v_nbRowsOld <> v_nbRowsNew THEN
      RAISE EXCEPTION 'E-Maj upgrade: internal error, the number of rows in the original emaj_sequence table (%) doesn''t match the number of rows in the new emaj_sequence table (%)',v_nbRowsOld, v_nbRowsNew;
    END IF;
    SELECT count(*) INTO v_nbRowsOld FROM emaj_seq_hole_old;
    SELECT count(*) INTO v_nbRowsNew FROM emaj.emaj_seq_hole;
    IF v_nbRowsOld <> v_nbRowsNew THEN
      RAISE EXCEPTION 'E-Maj upgrade: internal error, the number of rows in the original emaj_seq_hole table (%) doesn''t match the number of rows in the new emaj_seq_hole table (%)',v_nbRowsOld, v_nbRowsNew;
    END IF;
    SELECT count(*) INTO v_nbRowsOld FROM emaj_rlbk_old;
    SELECT count(*) INTO v_nbRowsNew FROM emaj.emaj_rlbk;
    IF v_nbRowsOld <> v_nbRowsNew THEN
      RAISE EXCEPTION 'E-Maj upgrade: internal error, the number of rows in the original emaj_rlbk table (%) doesn''t match the number of rows in the new emaj_rlbk table (%)',v_nbRowsOld, v_nbRowsNew;
    END IF;
    SELECT count(*) INTO v_nbRowsOld FROM emaj_rlbk_stat_old;
    SELECT count(*) INTO v_nbRowsNew FROM emaj.emaj_rlbk_stat;
    IF v_nbRowsOld <> v_nbRowsNew THEN
      RAISE EXCEPTION 'E-Maj upgrade: internal error, the number of rows in the original emaj_rlbk_stat table (%) doesn''t match the number of rows in the new emaj_rlbk_stat table (%)',v_nbRowsOld, v_nbRowsNew;
    END IF;
  END;
$do$;

DROP TABLE emaj_group_old;
DROP TABLE emaj_mark_old;
DROP TABLE emaj_sequence_old;
DROP TABLE emaj_seq_hole_old;
DROP TABLE emaj_rlbk_old;
DROP TABLE emaj_rlbk_stat_old;

------------------------------------
--                                --
-- emaj types                     --
--                                --
------------------------------------
CREATE TYPE emaj.emaj_consolidable_rollback_type AS (
  cons_group                   TEXT,                       -- group name
  cons_target_rlbk_mark_name   TEXT,                       -- name of the mark used as target of the logged rollback operation
  cons_target_rlbk_mark_id     BIGINT,                     -- id of the mark used as target of the logged rollback operation
  cons_end_rlbk_mark_name      TEXT,                       -- name of the mark set at the end of the logged rollback operation
  cons_end_rlbk_mark_id        BIGINT,                     -- id of the mark set at the end of the logged rollback operation
  cons_rows                    BIGINT,                     -- estimated number of update events that can be consolidated for the rollback
  cons_marks                   INT                         -- number of marks that would be deleted by a consolidation
  );
COMMENT ON TYPE emaj.emaj_consolidable_rollback_type IS
$$Represents the structure of rows returned by the emaj_get_consolidable_rollbacks() function.$$;

------------------------------------
--                                --
-- emaj functions                 --
--                                --
------------------------------------
--<begin_functions>                              pattern used by the tool that extracts and insert the functions definition
------------------------------------------------------------------
-- drop obsolete functions or functions with modified interface --
------------------------------------------------------------------
DROP FUNCTION emaj._get_mark_datetime(TEXT,TEXT);
DROP FUNCTION emaj._rlbk_tbl(R_REL EMAJ.EMAJ_RELATION,V_LASTGLOBALSEQ BIGINT,V_NBSESSION INT);
DROP FUNCTION emaj._delete_log_tbl(R_REL EMAJ.EMAJ_RELATION,V_TIMESTAMP TIMESTAMPTZ,V_LASTGLOBALSEQ BIGINT,V_LASTSEQUENCEID BIGINT,V_LASTSEQHOLEID BIGINT);
DROP FUNCTION emaj._rlbk_seq(R_REL EMAJ.EMAJ_RELATION,V_TIMESTAMP TIMESTAMPTZ,V_ISLOGGEDRLBK BOOLEAN,V_LASTSEQUENCEID BIGINT);
DROP FUNCTION emaj._log_stat_tbl(R_REL EMAJ.EMAJ_RELATION,V_TSFIRSTMARK TIMESTAMPTZ,V_TSLASTMARK TIMESTAMPTZ,V_FIRSTLASTSEQHOLEID BIGINT,V_LASTLASTSEQHOLEID BIGINT);
DROP FUNCTION emaj._gen_sql_tbl(R_REL EMAJ.EMAJ_RELATION,V_CONDITIONS TEXT);
DROP FUNCTION emaj.emaj_create_group(V_GROUPNAME TEXT);
DROP FUNCTION emaj.emaj_start_group(V_GROUPNAME TEXT,V_MARK TEXT);
DROP FUNCTION emaj.emaj_start_groups(V_GROUPNAMES TEXT[],V_MARK TEXT);
DROP FUNCTION emaj.emaj_stop_group(V_GROUPNAME TEXT);
DROP FUNCTION emaj.emaj_stop_groups(V_GROUPNAMES TEXT[]);
DROP FUNCTION emaj._set_mark_groups(V_GROUPNAMES TEXT[],V_MARK TEXT,V_MULTIGROUP BOOLEAN,V_EVENTTORECORD BOOLEAN);
DROP FUNCTION emaj.emaj_delete_mark_group(V_GROUPNAME TEXT,V_MARK TEXT);
DROP FUNCTION emaj.emaj_delete_before_mark_group(V_GROUPNAME TEXT,V_MARK TEXT);
DROP FUNCTION emaj._delete_before_mark_group(V_GROUPNAME TEXT,V_MARK TEXT);
DROP FUNCTION emaj.emaj_gen_sql_group(V_GROUPNAME TEXT,V_FIRSTMARK TEXT,V_LASTMARK TEXT,V_LOCATION TEXT);
DROP FUNCTION emaj.emaj_gen_sql_group(V_GROUPNAME TEXT,V_FIRSTMARK TEXT,V_LASTMARK TEXT,V_LOCATION TEXT,V_TBLSEQS TEXT[]);
DROP FUNCTION emaj.emaj_gen_sql_groups(V_GROUPNAMES TEXT[],V_FIRSTMARK TEXT,V_LASTMARK TEXT,V_LOCATION TEXT);
DROP FUNCTION emaj.emaj_gen_sql_groups(V_GROUPNAMES TEXT[],V_FIRSTMARK TEXT,V_LASTMARK TEXT,V_LOCATION TEXT,V_TBLSEQS TEXT[]);
DROP FUNCTION emaj._gen_sql_groups(V_GROUPNAMES TEXT[],V_FIRSTMARK TEXT,V_LASTMARK TEXT,V_LOCATION TEXT,V_TBLSEQS TEXT[]);

------------------------------------------------------------------
-- create new or modified functions                             --
------------------------------------------------------------------
CREATE OR REPLACE FUNCTION emaj._pg_version_num()
RETURNS INTEGER LANGUAGE sql IMMUTABLE AS
$$
-- This function returns as an integer the current postgresql version
SELECT current_setting('server_version_num')::int;
$$;

CREATE OR REPLACE FUNCTION emaj._set_time_stamp(CHAR(1))
RETURNS BIGINT LANGUAGE SQL AS
$$
-- this function inserts a new time stamp in the emaj_time_stamp table and returns the identifier of the new row
INSERT INTO emaj.emaj_time_stamp (time_last_emaj_gid, time_event)
  SELECT CASE WHEN is_called THEN last_value ELSE last_value - 1 END, $1 FROM emaj.emaj_global_seq
  RETURNING time_id;
$$;

CREATE OR REPLACE FUNCTION emaj._get_mark_time_id(TEXT, TEXT)
RETURNS BIGINT LANGUAGE sql AS
$$
-- This function returns the time stamp id of a mark, if exists, for a group,
--   processing the EMAJ_LAST_MARK keyword.
-- input: group name and mark name
-- output: mark time stamp id or NULL
SELECT CASE
         WHEN $2 = 'EMAJ_LAST_MARK' THEN
              (SELECT time_id FROM emaj.emaj_mark, emaj.emaj_time_stamp
                 WHERE time_id = mark_time_id AND mark_group = $1 ORDER BY time_id DESC LIMIT 1)
         ELSE (SELECT time_id FROM emaj.emaj_mark, emaj.emaj_time_stamp
                 WHERE time_id = mark_time_id AND mark_group = $1 AND mark_name = $2)
       END
$$;

CREATE OR REPLACE FUNCTION emaj._dblink_open_cnx(v_cnxName TEXT)
RETURNS INT LANGUAGE plpgsql AS
$_dblink_open_cnx$
-- This function tries to open a named dblink connection.
-- It uses as target: the current cluster (port), the current database and a role defined in the emaj_param table.
-- This role must be defined with a row having:
--   - param_key = 'dblink_user_password',
--   - param_value_text = 'user=<user> password=<password>' with the rules that apply to usual libPQ connect strings
-- The password can be omited if the connection doesn't require it.
-- The dblink_connect_u is used to open the connection so that emaj_adm but non superuser roles can access
--    cluster even when no password is required to log on.
-- Input:  connection name
-- Output: integer status return.
--           1 successful connection
--           0 already opened connection
--          -1 dblink is not installed
--          -2 dblink functions are not visible for the session
--          -3 dblink functions are not accessible by the role
--          -4 the transaction isolation level is not READ COMMITTED
--          -5 no 'dblink_user_password' parameter is defined in the emaj_param table
--          -6 error at dblink_connect() call
  DECLARE
    v_UserPassword           TEXT;
    v_connectString          TEXT;
    v_status                 INT;
  BEGIN
    IF (SELECT count(*) FROM pg_catalog.pg_proc WHERE proname = 'dblink_connect_u') = 0 THEN
      v_status = -1;                      -- dblink is not installed
    ELSIF (SELECT count(*) FROM pg_catalog.pg_proc
             WHERE proname = 'dblink_connect_u' AND pg_function_is_visible(oid)) = 0 THEN
      v_status = -2;                      -- dblink is not visible in the search_path
    ELSIF NOT has_function_privilege('dblink_connect_u(text, text)', 'execute') THEN
      v_status = -3;                      -- current role has not the execute rights on dblink functions
    ELSIF substring(v_cnxName FROM 1 FOR 5) = 'rlbk#' AND
          current_setting('transaction_isolation') <> 'read committed' THEN
      v_status = -4;                      -- 'rlbk#*' connection (used for rollbacks) must only come from a
                                          --   READ COMMITTED transaction
    ELSIF v_cnxName = ANY (dblink_get_connections()) THEN
-- dblink is usable, so search the requested connection name in dblink connections list
      v_status = 0;                       -- the requested connection is already open
    ELSE
-- so, get the 'dblink_user_password' parameter if exists, from emaj_param
      SELECT param_value_text INTO v_UserPassword FROM emaj.emaj_param WHERE param_key = 'dblink_user_password';
      IF NOT FOUND THEN
        v_status = -5;                    -- no 'dblink_user_password' parameter is defined in the emaj_param table
      ELSE
-- ... build the connect string
        v_connectString = 'host=localhost port=' || current_setting('port') ||
                          ' dbname=' || current_database() || ' ' || v_userPassword;
-- ... and try to connect
        BEGIN
          PERFORM dblink_connect_u(v_cnxName,v_connectString);
          v_status = 1;                 -- the connection is successful
        EXCEPTION
          WHEN OTHERS THEN
            v_status = -6;              -- the connection attempt failed
        END;
      END IF;
    END IF;
-- for connections used for rollback operations, record the dblink connection attempt in the emaj_hist table
    IF substring(v_cnxName FROM 1 FOR 5) = 'rlbk#' THEN
      INSERT INTO emaj.emaj_hist (hist_function, hist_object, hist_wording)
        VALUES ('DBLINK_OPEN_CNX',v_cnxName,'Status = ' || v_status);
    END IF;
    RETURN v_status;
  END;
$_dblink_open_cnx$;

CREATE OR REPLACE FUNCTION emaj._dblink_close_cnx(v_cnxName TEXT)
RETURNS VOID LANGUAGE plpgsql AS
$_dblink_close_cnx$
-- This function closes a named dblink connection.
-- Input:  connection name
  DECLARE
  BEGIN
    IF emaj._dblink_is_cnx_opened(v_cnxName) THEN
-- the emaj connection exists, so disconnect
      PERFORM dblink_disconnect(v_cnxName);
-- for connections used for rollback operations, record the dblink disconnection in the emaj_hist table
      IF substring(v_cnxName FROM 1 FOR 5) = 'rlbk#' THEN
        INSERT INTO emaj.emaj_hist (hist_function, hist_object)
          VALUES ('DBLINK_CLOSE_CNX',v_cnxName);
      END IF;
    END IF;
    RETURN;
  END;
$_dblink_close_cnx$;

CREATE OR REPLACE FUNCTION emaj._purge_hist()
RETURNS VOID LANGUAGE plpgsql AS
$_purge_hist$
-- This function purges the emaj history by deleting all rows prior the 'history_retention' parameter, but
--   not deleting event traces neither after the oldest active mark or after the oldest not committed or aborted rollback operation.
-- It also purges oldest rows from the emaj_rlbk_session and emaj_rlbk_plan tables, using the same rules.
-- The function is called at start group time and when oldest marks are deleted.
  DECLARE
    v_datetimeLimit          TIMESTAMPTZ;
    v_nbPurgedHist           BIGINT;
    v_maxRlbkId              BIGINT;
    v_nbPurgedRlbk           BIGINT;
    v_wording                TEXT = '';
  BEGIN
-- compute the timestamp limit
    SELECT MIN(datetime) FROM
      (                                           -- compute the timestamp limit from the history_retention parameter
        (SELECT current_timestamp -
           coalesce((SELECT param_value_interval FROM emaj.emaj_param WHERE param_key = 'history_retention'),'1 YEAR'))
      UNION ALL                                   -- get the transaction timestamp of the oldest non deleted mark for all groups
        (SELECT MIN(time_tx_timestamp) FROM emaj.emaj_time_stamp, emaj.emaj_mark
           WHERE time_id = mark_time_id AND NOT mark_is_deleted)
      UNION ALL                                   -- get the transaction timestamp of the oldest non committed or aborted rollback
        (SELECT MIN(time_tx_timestamp) FROM emaj.emaj_time_stamp, emaj.emaj_rlbk
           WHERE time_id = rlbk_time_id AND rlbk_status IN ('PLANNING', 'LOCKING', 'EXECUTING', 'COMPLETED'))
      ) AS t(datetime) INTO v_datetimeLimit;
-- delete oldest rows from emaj_hist
    DELETE FROM emaj.emaj_hist WHERE hist_datetime < v_datetimeLimit;
    GET DIAGNOSTICS v_nbPurgedHist = ROW_COUNT;
    IF v_nbPurgedHist > 0 THEN
      v_wording = v_nbPurgedHist || ' emaj_hist rows deleted';
    END IF;
-- get the greatest rollback identifier to purge
    SELECT MAX(rlbk_id) INTO v_maxRlbkId FROM emaj.emaj_rlbk, emaj.emaj_time_stamp
      WHERE time_id = rlbk_time_id AND time_tx_timestamp < v_datetimeLimit;
-- and purge emaj_rlbk_plan and emaj_rlbk_session tables
    IF v_maxRlbkId IS NOT NULL THEN
      DELETE FROM emaj.emaj_rlbk_plan WHERE rlbp_rlbk_id <= v_maxRlbkId;
      WITH deleted_rlbk AS (
        DELETE FROM emaj.emaj_rlbk_session
          WHERE rlbs_rlbk_id <= v_maxRlbkId
          RETURNING rlbs_rlbk_id
        )
        SELECT COUNT (DISTINCT rlbs_rlbk_id) INTO v_nbPurgedRlbk FROM deleted_rlbk;
      v_wording = v_wording || ' ; ' || v_nbPurgedRlbk || ' rollback events deleted';
    END IF;
-- record the purge into the history if there are significant data
    IF v_wording <> '' THEN
      INSERT INTO emaj.emaj_hist (hist_function, hist_wording)
        VALUES ('PURGE_HISTORY', v_wording);
    END IF;
    RETURN;
  END;
$_purge_hist$;

CREATE OR REPLACE FUNCTION emaj._check_names_array(v_names TEXT[], v_type TEXT)
RETURNS TEXT[] LANGUAGE plpgsql AS
$_check_names_array$
-- This function build a array of names similar to the supplied array, except that NULL
-- values, empty string and duplicate names are suppressed. Issue a warning if the result array is NULL.
-- The function is used to validate group names array or table and sequence names array.
-- Input: names array
--        type of element, used to format warning messages
-- Output: validated names array
  DECLARE
    v_outputNames            TEXT[];
    v_aName                  TEXT;
  BEGIN
    IF v_names IS NOT NULL AND array_upper(v_names,1) >= 1 THEN
-- if there are elements, build the result array
      FOREACH v_aName IN ARRAY v_names LOOP
-- look for not NULL & not empty name
        IF v_aName IS NULL OR v_aName = '' THEN
          RAISE WARNING '_check_names_array: a % name is NULL or empty.', v_type;
-- look for duplicate name
        ELSEIF v_outputNames IS NOT NULL AND v_aName = ANY (v_outputNames) THEN
          RAISE WARNING '_check_names_array: duplicate % name "%".', v_type, v_aName;
        ELSE
-- OK, keep the name
          v_outputNames = v_outputNames || v_aName;
        END IF;
      END LOOP;
    END IF;
-- check for NULL result
    IF v_outputNames IS NULL THEN
      RAISE WARNING '_check_names_array: No % name to process.', v_type;
    END IF;
    RETURN v_outputNames;
  END;
$_check_names_array$;

CREATE OR REPLACE FUNCTION emaj._check_group_content(v_groupName TEXT)
RETURNS VOID LANGUAGE plpgsql AS
$_check_group_content$
-- This function verifies that the content of tables group as defined into the emaj_group_def table is correct.
-- It is called by emaj_create_group() and emaj_alter_group() functions.
-- It checks that the referenced application tables and sequences,
--  - exist,
--  - is not located into an E-Maj schema (to protect against an E-Maj recursive use),
--  - do not already belong to another tables group,
--  - will not generate conflicts on emaj objects to create (when emaj names prefix is not the default one)
-- Input: the name of the tables group to check
  DECLARE
    v_msg                    TEXT;
  BEGIN
-- check that all application tables and sequences listed for the group really exist
    SELECT string_agg(full_name, ', ') INTO v_msg FROM (
      SELECT grpdef_schema || '.' || grpdef_tblseq AS full_name
        FROM emaj.emaj_group_def WHERE grpdef_group = v_groupName
      EXCEPT
      SELECT nspname || '.' || relname FROM pg_catalog.pg_class, pg_catalog.pg_namespace
        WHERE relnamespace = pg_namespace.oid AND relkind IN ('r','S')
      ORDER BY 1) AS t;
    IF v_msg IS NOT NULL THEN
      RAISE EXCEPTION '_check_group_content: one or several tables or sequences do not exist (%).', v_msg;
    END IF;
-- check no application schema listed for the group in the emaj_group_def table is an E-Maj schema
    SELECT string_agg(full_name, ', ') INTO v_msg FROM (
      SELECT grpdef_schema || '.' || grpdef_tblseq AS full_name
        FROM emaj.emaj_group_def
        WHERE grpdef_group = v_groupName
          AND grpdef_schema IN (
                SELECT DISTINCT rel_log_schema FROM emaj.emaj_relation
                UNION
                SELECT 'emaj')
        ORDER BY 1) AS t;
    IF v_msg IS NOT NULL THEN
      RAISE EXCEPTION '_check_group_content: one or several tables or sequences belong to an E-Maj schema (%).', v_msg;
    END IF;
-- check that no table or sequence of the new group already belongs to another created group
    SELECT string_agg(full_name, ', ') INTO v_msg FROM (
      SELECT grpdef_schema || '.' || grpdef_tblseq || ' in ' || rel_group AS full_name
        FROM emaj.emaj_group_def, emaj.emaj_relation
        WHERE grpdef_schema = rel_schema AND grpdef_tblseq = rel_tblseq
          AND grpdef_group = v_groupName AND rel_group <> v_groupName
      ORDER BY 1) AS t;
    IF v_msg IS NOT NULL THEN
      RAISE EXCEPTION '_check_group_content: one or several tables already belong to another group (%).', v_msg;
    END IF;
-- check that several tables of the group have not the same emaj names prefix
    SELECT string_agg(prefix, ', ') INTO v_msg FROM (
      SELECT coalesce(grpdef_emaj_names_prefix, grpdef_schema || '_' || grpdef_tblseq)  AS prefix, count(*)
        FROM emaj.emaj_group_def
        WHERE grpdef_group = v_groupName
      GROUP BY 1 HAVING count(*) > 1 ORDER BY 1) AS t;
    IF v_msg IS NOT NULL THEN
      RAISE EXCEPTION '_check_group_content: one or several emaj prefix are configured for several tables in the group (%).', v_msg;
    END IF;
-- check that emaj names prefix that will be generared will not generate conflict with objects from existing groups
    SELECT string_agg(prefix, ', ') INTO v_msg FROM (
      SELECT coalesce(grpdef_emaj_names_prefix, grpdef_schema || '_' || grpdef_tblseq) AS prefix
        FROM emaj.emaj_group_def, emaj.emaj_relation
        WHERE coalesce(grpdef_emaj_names_prefix, grpdef_schema || '_' || grpdef_tblseq) || '_log' = rel_log_table
          AND grpdef_group = v_groupName AND rel_group <> v_groupName
      ORDER BY 1) AS t;
    IF v_msg IS NOT NULL THEN
      RAISE EXCEPTION '_check_group_content: one or several emaj prefix are already used (%).', v_msg;
    END IF;
--
    RETURN;
  END;
$_check_group_content$;

CREATE OR REPLACE FUNCTION emaj._check_new_mark(v_mark TEXT, v_groupNames TEXT[])
RETURNS TEXT LANGUAGE plpgsql AS
$_check_new_mark$
-- This function verifies that a new mark name supplied the user is valid.
-- It processes the possible NULL mark value and the replacement of % wild characters.
-- It also checks that the mark name do not already exist for any group.
-- Input: name of the mark to set, array of group names
--        The array of group names may be NULL to avoid the check against groups
-- Output: internal name of the mark
  DECLARE
    v_markName               TEXT = v_mark;
    v_aGroupName             TEXT;
  BEGIN
-- check the mark name is not 'EMAJ_LAST_MARK'
    IF v_mark = 'EMAJ_LAST_MARK' THEN
       RAISE EXCEPTION '_check_new_mark: "%" is not an allowed name for a new mark.', v_mark;
    END IF;
-- process null or empty supplied mark name
    IF v_markName = '' OR v_markName IS NULL THEN
      v_markName = 'MARK_%';
    END IF;
-- process % wild characters in mark name
    v_markName = replace(v_markName, '%', to_char(current_timestamp, 'HH24.MI.SS.MS'));
-- if requested, check the existence of the mark in groups
    IF v_groupNames IS NOT NULL THEN
-- for each group of the array,
      FOREACH v_aGroupName IN ARRAY v_groupNames LOOP
-- ... if a mark with the same name already exists for the group, stop
        PERFORM 0 FROM emaj.emaj_mark
          WHERE mark_group = v_aGroupName AND mark_name = v_markName;
        IF FOUND THEN
           RAISE EXCEPTION '_check_new_mark: Group "%" already contains a mark named "%".', v_aGroupName, v_markName;
        END IF;
      END LOOP;
    END IF;
    RETURN v_markName;
  END;
$_check_new_mark$;

CREATE OR REPLACE FUNCTION emaj._create_log_schema(v_logSchemaName TEXT)
RETURNS VOID LANGUAGE plpgsql SECURITY DEFINER AS
$_create_log_schema$
-- The function creates a log schema and gives the appropriate rights to emaj users
-- Input: log schema name
-- The function is created as SECURITY DEFINER so that secondary schemas can be owned by superuser
  DECLARE
  BEGIN
-- check that the schema doesn't already exist
    PERFORM 0 FROM pg_catalog.pg_namespace WHERE nspname = v_logSchemaName;
    IF FOUND THEN
      RAISE EXCEPTION '_create_log_schema: schema "%" should not exist. Drop it manually, or modify emaj_group_def table''s content.',v_logSchemaName;
    END IF;
-- create the schema and give the appropriate rights
    EXECUTE 'CREATE SCHEMA ' || quote_ident(v_logSchemaName);
    EXECUTE 'GRANT ALL ON SCHEMA ' || quote_ident(v_logSchemaName) || ' TO emaj_adm';
    EXECUTE 'GRANT USAGE ON SCHEMA ' || quote_ident(v_logSchemaName) || ' TO emaj_viewer';
    RETURN;
  END;
$_create_log_schema$;

CREATE OR REPLACE FUNCTION emaj._drop_log_schema(v_logSchemaName TEXT, v_isForced BOOLEAN)
RETURNS VOID LANGUAGE plpgsql SECURITY DEFINER AS
$_drop_log_schema$
-- The function drops a log schema
-- Input: log schema name, boolean telling whether the schema to drop may contain residual objects
-- The function is created as SECURITY DEFINER so that secondary schemas can be dropped in any case
  DECLARE
  BEGIN
-- check that the schema exists
    PERFORM 0 FROM pg_catalog.pg_namespace WHERE nspname = v_logSchemaName;
    IF NOT FOUND THEN
      RAISE EXCEPTION '_drop_log_schema: internal error (schema "%" does not exist).',v_logSchemaName;
    END IF;
    IF v_isForced THEN
-- drop cascade when called by emaj_force_xxx_group()
      EXECUTE 'DROP SCHEMA ' || quote_ident(v_logSchemaName) || ' CASCADE';
    ELSE
-- otherwise, drop restrict with a trap on the potential error
      BEGIN
        EXECUTE 'DROP SCHEMA ' || quote_ident(v_logSchemaName);
        EXCEPTION
-- trap the 2BP01 exception to generate a more understandable error message
          WHEN DEPENDENT_OBJECTS_STILL_EXIST THEN         -- SQLSTATE '2BP01'
            RAISE EXCEPTION '_drop_log_schema: cannot drop schema "%". It probably owns unattended objects. Use the emaj_verify_all() function to get details', v_logSchemaName;
      END;
    END IF;
    RETURN;
  END;
$_drop_log_schema$;

CREATE OR REPLACE FUNCTION emaj._create_tbl(r_grpdef emaj.emaj_group_def, v_groupName TEXT, v_isRollbackable BOOLEAN, v_defTsp TEXT)
RETURNS VOID LANGUAGE plpgsql SECURITY DEFINER AS
$_create_tbl$
-- This function creates all what is needed to manage the log and rollback operations for an application table
-- Input: the emaj_group_def row related to the application table to process, the group name, a boolean indicating whether the group is rollbackable, and the default tablespace to use if no specific tablespace is set for this application table
-- Are created in the log schema:
--    - the associated log table, with its own sequence
--    - the function that logs the tables updates, defined as a trigger
-- The function is defined as SECURITY DEFINER so that emaj_adm role can use it even if he is not the owner of the application table.
  DECLARE
    v_emajSchema             TEXT = 'emaj';
    v_schemaPrefix           TEXT = 'emaj';
    v_emajNamesPrefix        TEXT;
    v_logSchema              TEXT;
    v_fullTableName          TEXT;
    v_logDatTsp              TEXT;
    v_logIdxTsp              TEXT;
    v_dataTblSpace           TEXT;
    v_idxTblSpace            TEXT;
    v_baseLogTableName       TEXT;
    v_baseLogIdxName         TEXT;
    v_baseLogFnctName        TEXT;
    v_baseSequenceName       TEXT;
    v_logTableName           TEXT;
    v_logIdxName             TEXT;
    v_logFnctName            TEXT;
    v_sequenceName           TEXT;
    v_relPersistence         CHAR(1);
    v_relhaspkey             BOOLEAN;
    v_stmt                   TEXT;
    v_triggerList            TEXT;
  BEGIN
-- check the table is neither a temporary nor an unlogged table
    SELECT relpersistence INTO v_relPersistence FROM pg_catalog.pg_class, pg_catalog.pg_namespace
      WHERE relnamespace = pg_namespace.oid AND nspname = r_grpdef.grpdef_schema AND relname = r_grpdef.grpdef_tblseq;
    IF v_relPersistence = 't' THEN
      RAISE EXCEPTION '_create_tbl: table "%.%" is a temporary table.', r_grpdef.grpdef_schema, r_grpdef.grpdef_tblseq;
    ELSIF v_relPersistence = 'u' THEN
      RAISE EXCEPTION '_create_tbl: table "%.%" is an unlogged table.', r_grpdef.grpdef_schema, r_grpdef.grpdef_tblseq;
    END IF;
-- check the table has a primary key
    SELECT true INTO v_relhaspkey FROM pg_catalog.pg_class, pg_catalog.pg_namespace, pg_catalog.pg_constraint
      WHERE relnamespace = pg_namespace.oid AND connamespace = pg_namespace.oid AND conrelid = pg_class.oid
        AND contype = 'p' AND nspname = r_grpdef.grpdef_schema AND relname = r_grpdef.grpdef_tblseq;
    IF NOT FOUND THEN
      v_relhaspkey = false;
    END IF;
    IF v_isRollbackable AND v_relhaspkey = FALSE THEN
      RAISE EXCEPTION '_create_tbl: table "%.%" has no PRIMARY KEY.', r_grpdef.grpdef_schema, r_grpdef.grpdef_tblseq;
    END IF;
-- build the prefix of all emaj object to create, by default <schema>_<table>
    v_emajNamesPrefix = coalesce(r_grpdef.grpdef_emaj_names_prefix, r_grpdef.grpdef_schema || '_' || r_grpdef.grpdef_tblseq);
-- build the name of emaj components associated to the application table (non schema qualified and not quoted)
    v_baseLogTableName     = v_emajNamesPrefix || '_log';
    v_baseLogIdxName       = v_emajNamesPrefix || '_log_idx';
    v_baseLogFnctName      = v_emajNamesPrefix || '_log_fnct';
    v_baseSequenceName     = v_emajNamesPrefix || '_log_seq';
-- build the different name for table, trigger, functions,...
    v_logSchema        = coalesce(v_schemaPrefix || r_grpdef.grpdef_log_schema_suffix, v_emajSchema);
    v_fullTableName    = quote_ident(r_grpdef.grpdef_schema) || '.' || quote_ident(r_grpdef.grpdef_tblseq);
    v_logTableName     = quote_ident(v_logSchema) || '.' || quote_ident(v_baseLogTableName);
    v_logIdxName       = quote_ident(v_baseLogIdxName);
    v_logFnctName      = quote_ident(v_logSchema) || '.' || quote_ident(v_baseLogFnctName);
    v_sequenceName     = quote_ident(v_logSchema) || '.' || quote_ident(v_baseSequenceName);
-- prepare TABLESPACE clauses for data and index
    v_logDatTsp = coalesce(r_grpdef.grpdef_log_dat_tsp, v_defTsp);
    v_logIdxTsp = coalesce(r_grpdef.grpdef_log_idx_tsp, v_defTsp);
    v_dataTblSpace = coalesce('TABLESPACE ' || quote_ident(v_logDatTsp),'');
    v_idxTblSpace = coalesce('TABLESPACE ' || quote_ident(v_logIdxTsp),'');
-- creation of the log table: the log table looks like the application table, with some additional technical columns
    EXECUTE 'DROP TABLE IF EXISTS ' || v_logTableName;
    EXECUTE 'CREATE TABLE ' || v_logTableName
         || ' (LIKE ' || v_fullTableName || ') ' || v_dataTblSpace;
    EXECUTE 'ALTER TABLE ' || v_logTableName
         || ' ADD COLUMN emaj_verb      VARCHAR(3),'
         || ' ADD COLUMN emaj_tuple     VARCHAR(3),'
         || ' ADD COLUMN emaj_gid       BIGINT      NOT NULL   DEFAULT nextval(''emaj.emaj_global_seq''),'
         || ' ADD COLUMN emaj_changed   TIMESTAMPTZ DEFAULT clock_timestamp(),'
         || ' ADD COLUMN emaj_txid      BIGINT      DEFAULT txid_current(),'
         || ' ADD COLUMN emaj_user      VARCHAR(32) DEFAULT session_user,'
         || ' ADD COLUMN emaj_user_ip   INET        DEFAULT inet_client_addr(),'
         || ' ADD COLUMN emaj_user_port INT         DEFAULT inet_client_port()';
-- creation of the index on the log table
    EXECUTE 'CREATE UNIQUE INDEX ' || v_logIdxName || ' ON '
         ||  v_logTableName || ' (emaj_gid, emaj_tuple) ' || v_idxTblSpace;
-- set the index associated to the primary key as cluster index. It may be useful for CLUSTER command.
    EXECUTE 'ALTER TABLE ONLY ' || v_logTableName || ' CLUSTER ON ' || v_logIdxName;
-- remove the NOT NULL constraints of application columns.
--   They are useless and blocking to store truncate event for tables belonging to audit_only tables
    SELECT string_agg(action, ',') INTO v_stmt FROM (
      SELECT ' ALTER COLUMN ' || quote_ident(attname) || ' DROP NOT NULL' AS action
        FROM pg_catalog.pg_attribute, pg_catalog.pg_class, pg_catalog.pg_namespace
        WHERE relnamespace = pg_namespace.oid AND attrelid = pg_class.oid
          AND nspname = v_logSchema AND relname = v_baseLogTableName
          AND attnum > 0 AND attnotnull AND attisdropped = false AND attname NOT LIKE E'emaj\\_%') AS t;
    IF v_stmt IS NOT NULL THEN
      EXECUTE 'ALTER TABLE ' || v_logTableName || v_stmt;
    END IF;
-- create the sequence associated to the log table
    EXECUTE 'CREATE SEQUENCE ' || v_sequenceName;
-- creation of the log fonction that will be mapped to the log trigger later
-- The new row is logged for each INSERT, the old row is logged for each DELETE
-- and the old and the new rows are logged for each UPDATE.
    EXECUTE 'CREATE OR REPLACE FUNCTION ' || v_logFnctName || '() RETURNS TRIGGER AS $logfnct$'
         || 'BEGIN'
-- The sequence associated to the log table is incremented at the beginning of the function ...
         || '  PERFORM NEXTVAL(' || quote_literal(v_sequenceName) || ');'
-- ... and the global id sequence is incremented by the first/only INSERT into the log table.
         || '  IF (TG_OP = ''DELETE'') THEN'
         || '    INSERT INTO ' || v_logTableName || ' SELECT OLD.*, ''DEL'', ''OLD'';'
         || '    RETURN OLD;'
         || '  ELSIF (TG_OP = ''UPDATE'') THEN'
         || '    INSERT INTO ' || v_logTableName || ' SELECT OLD.*, ''UPD'', ''OLD'';'
         || '    INSERT INTO ' || v_logTableName || ' SELECT NEW.*, ''UPD'', ''NEW'', lastval();'
         || '    RETURN NEW;'
         || '  ELSIF (TG_OP = ''INSERT'') THEN'
         || '    INSERT INTO ' || v_logTableName || ' SELECT NEW.*, ''INS'', ''NEW'';'
         || '    RETURN NEW;'
         || '  END IF;'
         || '  RETURN NULL;'
         || 'END;'
         || '$logfnct$ LANGUAGE plpgsql SECURITY DEFINER;';
-- creation of the log trigger on the application table, using the previously created log function
-- But the trigger is not immediately activated (it will be at emaj_start_group time)
    EXECUTE 'DROP TRIGGER IF EXISTS emaj_log_trg ON ' || v_fullTableName;
    EXECUTE 'CREATE TRIGGER emaj_log_trg'
         || ' AFTER INSERT OR UPDATE OR DELETE ON ' || v_fullTableName
         || '  FOR EACH ROW EXECUTE PROCEDURE ' || v_logFnctName || '()';
    EXECUTE 'ALTER TABLE ' || v_fullTableName || ' DISABLE TRIGGER emaj_log_trg';
-- creation of the trigger that manage any TRUNCATE on the application table
-- But the trigger is not immediately activated (it will be at emaj_start_group time)
    EXECUTE 'DROP TRIGGER IF EXISTS emaj_trunc_trg ON ' || v_fullTableName;
    IF v_isRollbackable THEN
-- For rollbackable groups, use the common _forbid_truncate_fnct() function that blocks the operation
      EXECUTE 'CREATE TRIGGER emaj_trunc_trg'
           || ' BEFORE TRUNCATE ON ' || v_fullTableName
           || '  FOR EACH STATEMENT EXECUTE PROCEDURE emaj._forbid_truncate_fnct()';
    ELSE
-- For audit_only groups, use the common _log_truncate_fnct() function that records the operation into the log table
      EXECUTE 'CREATE TRIGGER emaj_trunc_trg'
           || ' BEFORE TRUNCATE ON ' || v_fullTableName
           || '  FOR EACH STATEMENT EXECUTE PROCEDURE emaj._log_truncate_fnct()';
    END IF;
    EXECUTE 'ALTER TABLE ' || v_fullTableName || ' DISABLE TRIGGER emaj_trunc_trg';
-- register the table into emaj_relation
    INSERT INTO emaj.emaj_relation
               (rel_schema, rel_tblseq, rel_group, rel_priority, rel_log_schema,
                rel_log_dat_tsp, rel_log_idx_tsp, rel_kind, rel_log_table,
                rel_log_index, rel_log_sequence, rel_log_function)
        VALUES (r_grpdef.grpdef_schema, r_grpdef.grpdef_tblseq, r_grpdef.grpdef_group, r_grpdef.grpdef_priority, v_logSchema,
                v_logDatTsp, v_logIdxTsp, 'r', v_baseLogTableName,
                v_baseLogIdxName, v_baseSequenceName, v_baseLogFnctName);
--
-- check if the table has (neither internal - ie. created for fk - nor previously created by emaj) trigger
    SELECT string_agg(tgname, ', ') INTO v_triggerList FROM (
      SELECT tgname FROM pg_catalog.pg_trigger
        WHERE tgrelid = v_fullTableName::regclass AND tgconstraint = 0 AND tgname NOT LIKE E'emaj\\_%\\_trg') AS t;
-- if yes, issue a warning (if a trigger updates another table in the same table group or outside) it could generate problem at rollback time)
    IF v_triggerList IS NOT NULL THEN
      RAISE WARNING '_create_tbl: table "%" has triggers (%). Verify the compatibility with emaj rollback operations (in particular if triggers update one or several other tables). Triggers may have to be manualy disabled before rollback.', v_fullTableName, v_triggerList;
    END IF;
-- grant appropriate rights to both emaj roles
    EXECUTE 'GRANT SELECT ON TABLE ' || v_logTableName || ' TO emaj_viewer';
    EXECUTE 'GRANT ALL PRIVILEGES ON TABLE ' || v_logTableName || ' TO emaj_adm';
    EXECUTE 'GRANT SELECT ON SEQUENCE ' || v_sequenceName || ' TO emaj_viewer';
    EXECUTE 'GRANT ALL PRIVILEGES ON SEQUENCE ' || v_sequenceName || ' TO emaj_adm';
    RETURN;
  END;
$_create_tbl$;

CREATE OR REPLACE FUNCTION emaj._drop_tbl(r_rel emaj.emaj_relation)
RETURNS VOID LANGUAGE plpgsql SECURITY DEFINER AS
$_drop_tbl$
-- The function deletes all what has been created by _create_tbl function
-- Required inputs: row from emaj_relation corresponding to the appplication table to proccess
-- The function is defined as SECURITY DEFINER so that emaj_adm role can use it even if he is not the owner of the application table.
  DECLARE
    v_fullTableName          TEXT;
  BEGIN
    v_fullTableName    = quote_ident(r_rel.rel_schema) || '.' || quote_ident(r_rel.rel_tblseq);
-- check the table exists before dropping its triggers
    PERFORM 0 FROM pg_catalog.pg_class, pg_catalog.pg_namespace
      WHERE relnamespace = pg_namespace.oid
        AND nspname = r_rel.rel_schema AND relname = r_rel.rel_tblseq AND relkind = 'r';
    IF FOUND THEN
-- delete the log and truncate triggers on the application table
      EXECUTE 'DROP TRIGGER IF EXISTS emaj_log_trg ON ' || v_fullTableName;
      EXECUTE 'DROP TRIGGER IF EXISTS emaj_trunc_trg ON ' || v_fullTableName;
    END IF;
-- delete the log function
    EXECUTE 'DROP FUNCTION IF EXISTS ' || quote_ident(r_rel.rel_log_schema) || '.' || quote_ident(r_rel.rel_log_function) || '() CASCADE';
-- delete the sequence associated to the log table
    EXECUTE 'DROP SEQUENCE IF EXISTS ' || quote_ident(r_rel.rel_log_schema) || '.' || quote_ident(r_rel.rel_log_sequence);
-- delete the log table
    EXECUTE 'DROP TABLE IF EXISTS ' || quote_ident(r_rel.rel_log_schema) || '.' || quote_ident(r_rel.rel_log_table) || ' CASCADE';
-- delete rows related to the log sequence from emaj_sequence table
    DELETE FROM emaj.emaj_sequence WHERE sequ_schema = r_rel.rel_log_schema AND sequ_name = r_rel.rel_log_sequence;
-- delete rows related to the table from emaj_seq_hole table
    DELETE FROM emaj.emaj_seq_hole WHERE sqhl_schema = quote_ident(r_rel.rel_schema) AND sqhl_table = quote_ident(r_rel.rel_tblseq);
    RETURN;
  END;
$_drop_tbl$;

CREATE OR REPLACE FUNCTION emaj._create_seq(grpdef emaj.emaj_group_def, v_groupName TEXT)
RETURNS VOID LANGUAGE plpgsql AS
$_create_seq$
-- The function checks whether the sequence is related to a serial column of an application table.
-- If yes, it verifies that this table also belong to the same group
-- Required inputs: the emaj_group_def row related to the application sequence to process, the group name
  DECLARE
    v_tableSchema            TEXT;
    v_tableName              TEXT;
    v_tableGroup             TEXT;
  BEGIN
-- check no log schema has been set as parameter in the emaj_group_def table
    IF grpdef.grpdef_log_schema_suffix IS NOT NULL THEN
      RAISE EXCEPTION '_create_seq: Defining a secondary log schema is not allowed for a sequence (%.%).', grpdef.grpdef_schema, grpdef.grpdef_tblseq;
    END IF;
-- check no emaj name prefix has been set as parameter in the emaj_group_def table
    IF grpdef.grpdef_emaj_names_prefix IS NOT NULL THEN
      RAISE EXCEPTION '_create_seq: Defining an emaj names prefix is not allowed for a sequence (%.%).', grpdef.grpdef_schema, grpdef.grpdef_tblseq;
    END IF;
-- check no tablespace has been set as parameter in the emaj_group_def table
    IF grpdef.grpdef_log_dat_tsp IS NOT NULL OR grpdef.grpdef_log_idx_tsp IS NOT NULL THEN
      RAISE EXCEPTION '_create_seq: Defining log tablespaces is not allowed for a sequence (%.%).', grpdef.grpdef_schema, grpdef.grpdef_tblseq;
    END IF;
-- get the schema and the name of the table that contains a serial column this sequence is linked to, if one exists
    SELECT nt.nspname, ct.relname INTO v_tableSchema, v_tableName
      FROM pg_catalog.pg_class cs, pg_catalog.pg_namespace ns, pg_depend,
           pg_catalog.pg_class ct, pg_catalog.pg_namespace nt
      WHERE cs.relname = grpdef.grpdef_tblseq AND ns.nspname = grpdef.grpdef_schema -- the selected sequence
        AND cs.relnamespace = ns.oid                             -- join condition for sequence schema name
        AND ct.relnamespace = nt.oid                             -- join condition for linked table schema name
        AND pg_depend.objid = cs.oid                             -- join condition for the pg_depend table
        AND pg_depend.refobjid = ct.oid                          -- join conditions for depended table schema name
        AND pg_depend.classid = pg_depend.refclassid             -- the classid et refclassid must be 'pg_class'
        AND pg_depend.classid = (SELECT oid FROM pg_catalog.pg_class WHERE relname = 'pg_class');
    IF FOUND THEN
      SELECT grpdef_group INTO v_tableGroup FROM emaj.emaj_group_def
        WHERE grpdef_schema = v_tableSchema AND grpdef_tblseq = v_tableName;
      IF NOT FOUND THEN
        RAISE WARNING '_create_seq: Sequence %.% is linked to table %.% but this table does not belong to any tables group.', grpdef.grpdef_schema, grpdef.grpdef_tblseq, v_tableSchema, v_tableName;
      ELSE
        IF v_tableGroup <> v_groupName THEN
          RAISE WARNING '_create_seq: Sequence %.% is linked to table %.% but this table belong to another tables group (%).', grpdef.grpdef_schema, grpdef.grpdef_tblseq, v_tableSchema, v_tableName, v_tableGroup;
        END IF;
      END IF;
    END IF;
-- record the sequence in the emaj_relation table
      INSERT INTO emaj.emaj_relation (rel_schema, rel_tblseq, rel_group, rel_priority, rel_kind)
          VALUES (grpdef.grpdef_schema, grpdef.grpdef_tblseq, v_groupName, grpdef.grpdef_priority, 'S');
    RETURN;
  END;
$_create_seq$;

CREATE OR REPLACE FUNCTION emaj._drop_seq(r_rel emaj.emaj_relation)
RETURNS VOID LANGUAGE plpgsql AS
$_drop_seq$
-- The function deletes the rows stored into emaj_sequence for a particular sequence
-- Required inputs: row from emaj_relation corresponding to the appplication sequence to proccess
  BEGIN
-- delete rows from emaj_sequence
    EXECUTE 'DELETE FROM emaj.emaj_sequence WHERE sequ_schema = ' || quote_literal(r_rel.rel_schema) || ' AND sequ_name = ' || quote_literal(r_rel.rel_tblseq);
    RETURN;
  END;
$_drop_seq$;

CREATE OR REPLACE FUNCTION emaj._rlbk_tbl(r_rel emaj.emaj_relation, v_minGlobalSeq BIGINT, v_maxGlobalSeq BIGINT, v_nbSession INT, v_isLoggedRlbk BOOLEAN)
RETURNS BIGINT LANGUAGE plpgsql SECURITY DEFINER AS
$_rlbk_tbl$
-- This function rollbacks one table to a given point in time represented by the value of the global sequence
-- The function is called by emaj._rlbk_session_exec()
-- Input: row from emaj_relation corresponding to the appplication table to proccess
--        global sequence (non inclusive) lower and (inclusive) upper limits covering the rollback time frame
-- Output: number of rolled back primary keys
-- For unlogged rollback, the log triggers have been disabled previously and will be enabled later.
-- The function is defined as SECURITY DEFINER so that emaj_adm role can use it even if he is not the owner of the application table.
  DECLARE
    v_fullTableName          TEXT;
    v_logTableName           TEXT;
    v_tmpTable               TEXT;
    v_tableType              TEXT;
    v_nbPk                   BIGINT;
    v_colList                TEXT;
    v_pkColList              TEXT;
    v_pkCondList             TEXT;
  BEGIN
    v_fullTableName  = quote_ident(r_rel.rel_schema) || '.' || quote_ident(r_rel.rel_tblseq);
    v_logTableName   = quote_ident(r_rel.rel_log_schema) || '.' || quote_ident(r_rel.rel_log_table);
-- insert begin event in history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('ROLLBACK_TABLE', 'BEGIN', v_fullTableName, 'All log rows with emaj_gid > ' || v_minGlobalSeq || ' and <= ' || v_maxGlobalSeq);
-- Build some pieces of SQL statements
--   build the tables's columns list
    SELECT string_agg(col_name, ',') INTO v_colList FROM (
      SELECT 'tbl.' || quote_ident(attname) AS col_name FROM pg_catalog.pg_attribute
        WHERE attrelid = v_fullTableName::regclass
          AND attnum > 0 AND NOT attisdropped
        ORDER BY attnum) AS t;
--   build the pkey columns list and the "equality on the primary key" conditions
    SELECT string_agg(col_pk_name, ','), string_agg(col_pk_cond, ' AND ') INTO v_pkColList, v_pkCondList FROM (
      SELECT quote_ident(attname) AS col_pk_name,
             'tbl.' || quote_ident(attname) || ' = keys.' || quote_ident(attname) AS col_pk_cond
        FROM pg_catalog.pg_attribute, pg_catalog.pg_index
        WHERE pg_attribute.attrelid = pg_index.indrelid
          AND attnum = ANY (indkey)
          AND indrelid = v_fullTableName::regclass AND indisprimary
          AND attnum > 0 AND attisdropped = false
        ORDER BY attnum) AS t;
-- internal check that lists are not NULL (they should not be)
    IF v_colList IS NULL OR v_pkColList IS NULL OR v_pkCondList IS NULL THEN
      RAISE EXCEPTION '_rlbk_tbl: internal error (at least one list is NULL (columns list = %, pk columns list = %, conditions list = %).',v_colList, v_pkColList, v_pkCondList;
    END IF;
-- create the temporary table containing all primary key values with their earliest emaj_gid
    IF v_nbSession = 1 THEN
      v_tableType = 'TEMP';
      v_tmpTable = 'emaj_tmp_' || pg_backend_pid();
    ELSE
--   with multi session parallel rollbacks, the table cannot be a TEMP table because it would not be usable in 2PC
--   but it may be an UNLOGGED table
      v_tableType = 'UNLOGGED';
      v_tmpTable = 'emaj.emaj_tmp_' || pg_backend_pid();
    END IF;
    EXECUTE 'CREATE ' || v_tableType || ' TABLE ' || v_tmpTable || ' AS '
         || '  SELECT ' || v_pkColList || ', min(emaj_gid) as emaj_gid'
         || '    FROM ' || v_logTableName
--         || '    WHERE emaj_gid > ' || v_minGlobalSeq
         || '    WHERE emaj_gid > ' || v_minGlobalSeq || 'AND emaj_gid <= ' || v_maxGlobalSeq
         || '    GROUP BY ' || v_pkColList;
    GET DIAGNOSTICS v_nbPk = ROW_COUNT;
-- delete all rows from the application table corresponding to each touched primary key
--   this deletes rows inserted or updated during the rolled back period
    EXECUTE 'DELETE FROM ONLY ' || v_fullTableName || ' tbl USING ' || v_tmpTable || ' keys '
         || '  WHERE ' || v_pkCondList;
-- for logged rollbacks, if the number of pkey to process is greater than 1.000, ANALYZE the log table to take into account
--   the impact of just inserted rows, avoiding a potentialy bad plan for the next INSERT statement
    IF v_isLoggedRlbk AND v_nbPk > 1000 THEN
      EXECUTE 'ANALYZE ' || v_logTableName;
    END IF;
-- insert into the application table rows that were deleted or updated during the rolled back period
    EXECUTE 'INSERT INTO ' || v_fullTableName
         || '  SELECT ' || v_colList
         || '    FROM ' || v_logTableName || ' tbl, ' || v_tmpTable || ' keys '
         || '    WHERE ' || v_pkCondList || ' AND tbl.emaj_gid = keys.emaj_gid AND tbl.emaj_tuple = ''OLD'''
         || '      AND tbl.emaj_gid > ' || v_minGlobalSeq || 'AND tbl.emaj_gid <= ' || v_maxGlobalSeq;
-- drop the now useless temporary table
    EXECUTE 'DROP TABLE ' || v_tmpTable;
-- insert end event in history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('ROLLBACK_TABLE', 'END', v_fullTableName, v_nbPk || ' rolled back primary keys');
    RETURN v_nbPk;
  END;
$_rlbk_tbl$;

CREATE OR REPLACE FUNCTION emaj._delete_log_tbl(r_rel emaj.emaj_relation, v_beginTimeId BIGINT, v_endTimeId BIGINT, v_lastGlobalSeq BIGINT)
RETURNS BIGINT LANGUAGE plpgsql AS
$_delete_log_tbl$
-- This function deletes the part of a log table corresponding to updates that have been rolled back.
-- The function is only called by emaj._rlbk_session_exec(), for unlogged rollbacks.
-- It deletes sequences records corresponding to marks that are not visible anymore after the rollback.
-- It also registers the hole in sequence numbers generated by the deleted log rows.
-- Input: row from emaj_relation corresponding to the appplication table to proccess,
--        begin and end time stamp ids to define the time range identifying the hole to create in the log sequence
--        global sequence value limit for rollback, mark timestamp,
--        flag to specify if the rollback is logged
-- Output: deleted rows
  DECLARE
    v_nbRows                 BIGINT;
  BEGIN
-- delete obsolete log rows
    EXECUTE 'DELETE FROM ' || quote_ident(r_rel.rel_log_schema) || '.' || quote_ident(r_rel.rel_log_table) || ' WHERE emaj_gid > ' || v_lastGlobalSeq;
    GET DIAGNOSTICS v_nbRows = ROW_COUNT;
-- record the sequence holes generated by the delete operation
-- this is due to the fact that log sequences are not rolled back, this information will be used by the emaj_log_stat_group
--   function (and indirectly by emaj_estimate_rollback_duration())
-- first delete, if exist, sequence holes that have disappeared with the rollback
    DELETE FROM emaj.emaj_seq_hole
      WHERE sqhl_schema = r_rel.rel_schema AND sqhl_table = r_rel.rel_tblseq
        AND sqhl_begin_time_id >= v_beginTimeId AND sqhl_begin_time_id < v_endTimeId;
-- and then insert the new sequence hole
    EXECUTE 'INSERT INTO emaj.emaj_seq_hole (sqhl_schema, sqhl_table, sqhl_begin_time_id, sqhl_end_time_id, sqhl_hole_size) VALUES ('
      || quote_literal(r_rel.rel_schema) || ',' || quote_literal(r_rel.rel_tblseq) || ',' || v_beginTimeId || ',' || v_endTimeId || ', ('
      || ' SELECT CASE WHEN is_called THEN last_value + increment_by ELSE last_value END FROM '
      || quote_ident(r_rel.rel_log_schema) || '.' || quote_ident(r_rel.rel_log_sequence)
      || ')-('
      || ' SELECT CASE WHEN sequ_is_called THEN sequ_last_val + sequ_increment ELSE sequ_last_val END FROM '
      || ' emaj.emaj_sequence WHERE'
      || ' sequ_schema = ' || quote_literal(r_rel.rel_log_schema)
      || ' AND sequ_name = ' || quote_literal(r_rel.rel_log_sequence)
      || ' AND sequ_time_id = ' || v_beginTimeId || '))';
    RETURN v_nbRows;
  END;
$_delete_log_tbl$;

CREATE OR REPLACE FUNCTION emaj._rlbk_seq(r_rel emaj.emaj_relation, v_timeId BIGINT)
RETURNS VOID LANGUAGE plpgsql SECURITY DEFINER AS
$_rlbk_seq$
-- This function rollbacks one application sequence to a given mark
-- The function is called by emaj.emaj._rlbk_end()
-- Input: the emaj_group_def row related to the application sequence to process, time id of the mark to rollback to
-- The function is defined as SECURITY DEFINER so that emaj_adm role can use it even if it is not the owner of the application sequence.
  DECLARE
    v_fullSeqName            TEXT;
    v_stmt                   TEXT;
    mark_seq_rec             RECORD;
    curr_seq_rec             RECORD;
  BEGIN
-- Read sequence's characteristics at mark time
    BEGIN
      SELECT sequ_schema, sequ_name, sequ_last_val, sequ_start_val, sequ_increment,
             sequ_max_val, sequ_min_val, sequ_cache_val, sequ_is_cycled, sequ_is_called
        INTO STRICT mark_seq_rec
        FROM emaj.emaj_sequence
        WHERE sequ_schema = r_rel.rel_schema AND sequ_name = r_rel.rel_tblseq AND sequ_time_id = v_timeId;
      EXCEPTION
        WHEN NO_DATA_FOUND THEN
          RAISE EXCEPTION '_rlbk_seq: Mark at time id "%" not found for sequence "%.%".', v_timeId, r_rel.rel_schema, r_rel.rel_tblseq;
    END;
-- Read the current sequence's characteristics
    v_fullSeqName = quote_ident(r_rel.rel_schema) || '.' || quote_ident(r_rel.rel_tblseq);
    EXECUTE 'SELECT last_value, start_value, increment_by, max_value, min_value, cache_value, is_cycled, is_called FROM '
             || v_fullSeqName
            INTO STRICT curr_seq_rec;
-- Build the ALTER SEQUENCE statement, depending on the differences between the present values and the related
--   values at the requested mark time
    v_stmt='';
    IF curr_seq_rec.last_value <> mark_seq_rec.sequ_last_val OR
       curr_seq_rec.is_called <> mark_seq_rec.sequ_is_called THEN
      IF mark_seq_rec.sequ_is_called THEN
        v_stmt=v_stmt || ' RESTART ' || mark_seq_rec.sequ_last_val + mark_seq_rec.sequ_increment;
      ELSE
        v_stmt=v_stmt || ' RESTART ' || mark_seq_rec.sequ_last_val;
      END IF;
    END IF;
    IF curr_seq_rec.start_value <> mark_seq_rec.sequ_start_val THEN
      v_stmt=v_stmt || ' START ' || mark_seq_rec.sequ_start_val;
    END IF;
    IF curr_seq_rec.increment_by <> mark_seq_rec.sequ_increment THEN
      v_stmt=v_stmt || ' INCREMENT ' || mark_seq_rec.sequ_increment;
    END IF;
    IF curr_seq_rec.min_value <> mark_seq_rec.sequ_min_val THEN
      v_stmt=v_stmt || ' MINVALUE ' || mark_seq_rec.sequ_min_val;
    END IF;
    IF curr_seq_rec.max_value <> mark_seq_rec.sequ_max_val THEN
      v_stmt=v_stmt || ' MAXVALUE ' || mark_seq_rec.sequ_max_val;
    END IF;
    IF curr_seq_rec.cache_value <> mark_seq_rec.sequ_cache_val THEN
      v_stmt=v_stmt || ' CACHE ' || mark_seq_rec.sequ_cache_val;
    END IF;
    IF curr_seq_rec.is_cycled <> mark_seq_rec.sequ_is_cycled THEN
      IF mark_seq_rec.sequ_is_cycled = 'f' THEN
        v_stmt=v_stmt || ' NO ';
      END IF;
      v_stmt=v_stmt || ' CYCLE ';
    END IF;
-- and execute the statement if at least one parameter has changed
    IF v_stmt <> '' THEN
      EXECUTE 'ALTER SEQUENCE ' || v_fullSeqName || v_stmt;
    END IF;
-- insert event in history
    INSERT INTO emaj.emaj_hist (hist_function, hist_object, hist_wording)
      VALUES ('ROLLBACK_SEQUENCE', v_fullSeqName, substr(v_stmt,2));
    RETURN;
  END;
$_rlbk_seq$;

CREATE OR REPLACE FUNCTION emaj._log_stat_tbl(r_rel emaj.emaj_relation, v_beginTimeId BIGINT, v_endTimeId BIGINT)
RETURNS BIGINT LANGUAGE plpgsql AS
$_log_stat_tbl$
-- This function returns the number of log rows for a single table between 2 time stamps or between a time stamp and the current situation.
-- It is called by the emaj_log_stat_group(), _rlbk_planning(), _rlbk_start_mark() and _gen_sql_groups() functions.
-- These statistics are computed using the serial id of log tables and holes is sequences recorded into emaj_seq_hole at rollback time or
-- rollback consolidation time.
-- Input: schema name and table name, log schema, the time stamp ids defining the time range to examine
--   a end time stamp id set to NULL indicates the current situation
-- Output: number of log rows between both marks for the table
  DECLARE
    v_beginLastValue         BIGINT;
    v_endLastValue           BIGINT;
    v_sumHole                BIGINT;
  BEGIN
-- get the log table id at begin time id
    SELECT CASE WHEN sequ_is_called THEN sequ_last_val ELSE sequ_last_val - sequ_increment END INTO v_beginLastValue
       FROM emaj.emaj_sequence
       WHERE sequ_schema = r_rel.rel_log_schema
         AND sequ_name = r_rel.rel_log_sequence
         AND sequ_time_id = v_beginTimeId;
    IF v_endTimeId IS NULL THEN
-- last time id is NULL, so examine the current state of the log table id
      EXECUTE 'SELECT CASE WHEN is_called THEN last_value ELSE last_value - increment_by END FROM '
           || quote_ident(r_rel.rel_log_schema) || '.' || quote_ident(r_rel.rel_log_sequence) INTO v_endLastValue;
--   and count the sum of hole from the start time to now
      SELECT coalesce(sum(sqhl_hole_size),0) INTO v_sumHole FROM emaj.emaj_seq_hole
        WHERE sqhl_schema = r_rel.rel_schema AND sqhl_table = r_rel.rel_tblseq
          AND sqhl_begin_time_id >= v_beginTimeId;
    ELSE
-- last time id is not NULL, so get the log table id at end time id
      SELECT CASE WHEN sequ_is_called THEN sequ_last_val ELSE sequ_last_val - sequ_increment END INTO v_endLastValue
         FROM emaj.emaj_sequence
         WHERE sequ_schema = r_rel.rel_log_schema
           AND sequ_name = r_rel.rel_log_sequence
           AND sequ_time_id = v_endTimeId;
--   and count the sum of hole from the start time to the end time
      SELECT coalesce(sum(sqhl_hole_size),0) INTO v_sumHole FROM emaj.emaj_seq_hole
        WHERE sqhl_schema = r_rel.rel_schema AND sqhl_table = r_rel.rel_tblseq
          AND sqhl_begin_time_id >= v_beginTimeId AND sqhl_end_time_id <= v_endTimeId;
    END IF;
-- return the stat row for the table
    RETURN (v_endLastValue - v_beginLastValue - v_sumHole);
  END;
$_log_stat_tbl$;

CREATE OR REPLACE FUNCTION emaj._gen_sql_tbl(r_rel emaj.emaj_relation, v_conditions TEXT)
RETURNS BIGINT LANGUAGE plpgsql SECURITY DEFINER SET standard_conforming_strings = ON AS
$_gen_sql_tbl$
-- This function generates SQL commands representing all updates performed on a table between 2 marks
-- or beetween a mark and the current situation. These command are stored into a temporary table created
-- by the _gen_sql_groups() calling function.
-- Input: - fully qualified application table to process
--        - fully qualified associated log table
--        - sql conditions corresponding to the marks range to process
-- Output: number of generated SQL statements
  DECLARE
    v_fullTableName          TEXT;
    v_logTableName           TEXT;
    v_valList                TEXT;
    v_setList                TEXT;
    v_pkCondList             TEXT;
    v_unquotedType           TEXT[] = array['smallint','integer','bigint','numeric','decimal',
                                             'int2','int4','int8','serial','bigserial',
                                             'real','double precision','float','float4','float8','oid'];
    v_rqInsert               TEXT;
    v_rqUpdate               TEXT;
    v_rqDelete               TEXT;
    v_rqTruncate             TEXT;
    v_nbSQL                  BIGINT;
    r_col                    RECORD;
  BEGIN
-- build schema specified table name and log table name
    v_fullTableName = quote_ident(r_rel.rel_schema) || '.' || quote_ident(r_rel.rel_tblseq);
    v_logTableName = quote_ident(r_rel.rel_log_schema) || '.' || quote_ident(r_rel.rel_log_table);
-- retrieve from pg_attribute all columns of the application table and build :
-- - the VALUES list used in the INSERT statements
-- - the SET list used in the UPDATE statements
    v_valList = '';
    v_setList = '';
    FOR r_col IN
      SELECT attname, format_type(atttypid,atttypmod) FROM pg_catalog.pg_attribute
       WHERE attrelid = v_fullTableName ::regclass
         AND attnum > 0 AND NOT attisdropped
       ORDER BY attnum
    LOOP
-- test if the column format (up to the parenthesis) belongs to the list of formats that do not require any quotation (like numeric data types)
      IF regexp_replace(r_col.format_type,E'\\(.*$','') = ANY(v_unquotedType) THEN
-- literal for this column can remain as is
        v_valList = v_valList || ''' || coalesce(o.' || quote_ident(r_col.attname) || '::text,''NULL'') || '', ';
        v_setList = v_setList || quote_ident(replace(r_col.attname,'''','''''')) || ' = '' || coalesce(n.' || quote_ident(r_col.attname) || ' ::text,''NULL'') || '', ';
      ELSE
-- literal for this column must be quoted
        v_valList = v_valList || ''' || quote_nullable(o.' || quote_ident(r_col.attname) || ') || '', ';
        v_setList = v_setList || quote_ident(replace(r_col.attname,'''','''''')) || ' = '' || quote_nullable(n.' || quote_ident(r_col.attname) || ') || '', ';
      END IF;
    END LOOP;
-- suppress the final separators
    v_valList = substring(v_valList FROM 1 FOR char_length(v_valList) - 2);
    v_setList = substring(v_setList FROM 1 FOR char_length(v_setList) - 2);
-- retrieve all columns that represents the pkey and build the "pkey equal" conditions set that will be used in UPDATE and DELETE statements
-- (taking column names in pg_attribute from the table's definition instead of index definition is mandatory
--  starting from pg9.0, joining tables with indkey instead of indexrelid)
    v_pkCondList = '';
    FOR r_col IN
      SELECT attname, format_type(atttypid,atttypmod) FROM pg_catalog.pg_attribute, pg_catalog.pg_index
        WHERE pg_attribute.attrelid = pg_index.indrelid
          AND attnum = ANY (indkey)
          AND indrelid = v_fullTableName ::regclass AND indisprimary
          AND attnum > 0 AND NOT attisdropped
    LOOP
-- test if the column format (at least up to the parenthesis) belongs to the list of formats that do not require any quotation (like numeric data types)
      IF regexp_replace (r_col.format_type,E'\\(.*$','') = ANY(v_unquotedType) THEN
-- literal for this column can remain as is
--          v_pkCondList = v_pkCondList || quote_ident(replace(r_col.attname,'''','''''')) || ' = '' || o.' || quote_ident(r_col.attname) || ' || ''::' || r_col.format_type || ' AND ';
        v_pkCondList = v_pkCondList || quote_ident(replace(r_col.attname,'''','''''')) || ' = '' || o.' || quote_ident(r_col.attname) || ' || '' AND ';
      ELSE
-- literal for this column must be quoted
--          v_pkCondList = v_pkCondList || quote_ident(replace(r_col.attname,'''','''''')) || ' = '' || quote_literal(o.' || quote_ident(r_col.attname) || ') || ''::' || r_col.format_type || ' AND ';
        v_pkCondList = v_pkCondList || quote_ident(replace(r_col.attname,'''','''''')) || ' = '' || quote_literal(o.' || quote_ident(r_col.attname) || ') || '' AND ';
      END IF;
    END LOOP;
-- suppress the final separator
    v_pkCondList = substring(v_pkCondList FROM 1 FOR char_length(v_pkCondList) - 5);
-- prepare sql skeletons for each statement type
    v_rqInsert = '''INSERT INTO ' || replace(v_fullTableName,'''','''''') || ' VALUES (' || v_valList || ');''';
    v_rqUpdate = '''UPDATE ONLY ' || replace(v_fullTableName,'''','''''') || ' SET ' || v_setList || ' WHERE ' || v_pkCondList || ';''';
    v_rqDelete = '''DELETE FROM ONLY ' || replace(v_fullTableName,'''','''''') || ' WHERE ' || v_pkCondList || ';''';
    v_rqTruncate = '''TRUNCATE ' || replace(v_fullTableName,'''','''''') || ';''';
-- now scan the log table to process all statement types at once
    EXECUTE 'INSERT INTO emaj_temp_script '
         || 'SELECT o.emaj_gid, 0, o.emaj_txid, CASE '
         ||   ' WHEN o.emaj_verb = ''INS'' THEN ' || v_rqInsert
         ||   ' WHEN o.emaj_verb = ''UPD'' AND o.emaj_tuple = ''OLD'' THEN ' || v_rqUpdate
         ||   ' WHEN o.emaj_verb = ''DEL'' THEN ' || v_rqDelete
         ||   ' WHEN o.emaj_verb = ''TRU'' THEN ' || v_rqTruncate
         || ' END '
         || ' FROM ' || v_logTableName || ' o'
         ||   ' LEFT OUTER JOIN ' || v_logTableName || ' n ON n.emaj_gid = o.emaj_gid'
         || '        AND (n.emaj_verb = ''UPD'' AND n.emaj_tuple = ''NEW'') '
         || ' WHERE NOT (o.emaj_verb = ''UPD'' AND o.emaj_tuple = ''NEW'')'
         || ' AND ' || v_conditions;
    GET DIAGNOSTICS v_nbSQL = ROW_COUNT;
    RETURN v_nbSQL;
  END;
$_gen_sql_tbl$;

CREATE OR REPLACE FUNCTION emaj._verify_groups(v_groups TEXT[], v_onErrorStop BOOLEAN)
RETURNS SETOF emaj._verify_groups_type LANGUAGE plpgsql AS
$_verify_groups$
-- The function verifies the consistency of a tables groups array.
-- Input: - tables groups array,
--        - a boolean indicating whether the function has to raise an exception in case of detected unconsistency.
-- If onErrorStop boolean is false, it returns a set of _verify_groups_type records, one row per detected unconsistency, including the faulting schema and table or sequence names and a detailed message.
-- If no error is detected, no row is returned.
  DECLARE
    v_hint                   TEXT = 'You may use "SELECT * FROM emaj.emaj_verify_all()" to look for other issues.';
    r_object                 RECORD;
  BEGIN
-- Note that there is no check that the supplied groups exist. This has already been done by all calling functions.
-- Let's start with some global checks that always raise an exception if an issue is detected
-- check the postgres version: E-Maj needs postgres 9.1+
    IF emaj._pg_version_num() < 90100 THEN
      RAISE EXCEPTION 'The current postgres version (%) is not compatible with E-Maj.', version();
    END IF;
-- OK, now look for groups unconsistency
-- Unlike emaj_verify_all(), there is no direct check that application schemas exist
-- check all application relations referenced in the emaj_relation table still exist
    FOR r_object IN
      SELECT t.rel_schema, t.rel_tblseq,
             'In group "' || r.rel_group || '", the ' ||
               CASE WHEN t.rel_kind = 'r' THEN 'table "' ELSE 'sequence "' END ||
               t.rel_schema || '"."' || t.rel_tblseq || '" does not exist any more.' AS msg
        FROM (                                    -- all relations known by E-Maj
          SELECT rel_schema, rel_tblseq, rel_kind FROM emaj.emaj_relation WHERE rel_group = ANY (v_groups)
            EXCEPT                                -- all relations known by postgres
          SELECT nspname, relname, relkind FROM pg_catalog.pg_class, pg_catalog.pg_namespace
            WHERE relnamespace = pg_namespace.oid AND relkind IN ('r','S')
             ) AS t, emaj.emaj_relation r         -- join with emaj_relation to get the group name
        WHERE t.rel_schema = r.rel_schema AND t.rel_tblseq = r.rel_tblseq
        ORDER BY 1,2,3
    LOOP
      IF v_onErrorStop THEN RAISE EXCEPTION '_verify_groups (1): % %',r_object.msg,v_hint; END IF;
      RETURN NEXT r_object;
    END LOOP;
-- check the log table for all tables referenced in the emaj_relation table still exist
    FOR r_object IN
      SELECT rel_schema, rel_tblseq,
             'In group "' || rel_group || '", the log table "' ||
               rel_log_schema || '"."' || rel_log_table || '" is not found.' AS msg
        FROM emaj.emaj_relation
        WHERE rel_group = ANY (v_groups)
          AND rel_kind = 'r'
          AND NOT EXISTS
              (SELECT NULL FROM pg_catalog.pg_namespace, pg_catalog.pg_class
                 WHERE nspname = rel_log_schema AND relname = rel_log_table
                   AND relnamespace = pg_namespace.oid)
        ORDER BY 1,2,3
    LOOP
      IF v_onErrorStop THEN RAISE EXCEPTION '_verify_groups (2): % %',r_object.msg,v_hint; END IF;
      RETURN NEXT r_object;
    END LOOP;
-- check the log function for each table referenced in the emaj_relation table still exists
    FOR r_object IN
                                                  -- the schema and table names are rebuilt from the returned function name
      SELECT rel_schema, rel_tblseq,
             'In group "' || rel_group || '", the log function "' || rel_log_schema || '"."' || rel_log_function || '" is not found.' AS msg
        FROM emaj.emaj_relation
        WHERE rel_group = ANY (v_groups) AND rel_kind = 'r'
          AND NOT EXISTS
              (SELECT NULL FROM pg_catalog.pg_proc, pg_catalog.pg_namespace
                 WHERE nspname = rel_log_schema AND proname = rel_log_function
                   AND pronamespace = pg_namespace.oid)
        ORDER BY 1,2,3
    LOOP
      IF v_onErrorStop THEN RAISE EXCEPTION '_verify_groups (3): % %',r_object.msg,v_hint; END IF;
      RETURN NEXT r_object;
    END LOOP;
-- check log and truncate triggers for all tables referenced in the emaj_relation table still exist
--   start with log trigger
    FOR r_object IN
      SELECT rel_schema, rel_tblseq,
             'In group "' || rel_group || '", the log trigger "emaj_log_trg" on table "' ||
               rel_schema || '"."' || rel_tblseq || '" is not found.' AS msg
        FROM emaj.emaj_relation
        WHERE rel_group = ANY (v_groups) AND rel_kind = 'r'
          AND NOT EXISTS
              (SELECT NULL FROM pg_catalog.pg_trigger, pg_catalog.pg_namespace, pg_catalog.pg_class
                 WHERE nspname = rel_schema AND relname = rel_tblseq AND tgname = 'emaj_log_trg'
                   AND tgrelid = pg_class.oid AND relnamespace = pg_namespace.oid)
        ORDER BY 1,2,3
    LOOP
      IF v_onErrorStop THEN RAISE EXCEPTION '_verify_groups (4): % %',r_object.msg,v_hint; END IF;
      RETURN NEXT r_object;
    END LOOP;
--   then truncate trigger
    FOR r_object IN
      SELECT rel_schema, rel_tblseq,
             'In group "' || rel_group || '", the truncate trigger "emaj_trunc_trg" on table "' ||
             rel_schema || '"."' || rel_tblseq || '" is not found.' AS msg
        FROM emaj.emaj_relation
      WHERE rel_group = ANY (v_groups) AND rel_kind = 'r'
          AND NOT EXISTS
              (SELECT NULL FROM pg_catalog.pg_trigger, pg_catalog.pg_namespace, pg_catalog.pg_class
                 WHERE nspname = rel_schema AND relname = rel_tblseq AND tgname = 'emaj_trunc_trg'
                   AND tgrelid = pg_class.oid AND relnamespace = pg_namespace.oid)
      ORDER BY 1,2,3
    LOOP
      IF v_onErrorStop THEN RAISE EXCEPTION '_verify_groups (5): % %',r_object.msg,v_hint; END IF;
      RETURN NEXT r_object;
    END LOOP;
-- check all log tables have a structure consistent with the application tables they reference
--      (same columns and same formats). It only returns one row per faulting table.
    FOR r_object IN
      WITH cte_app_tables_columns AS (                -- application table's columns
          SELECT rel_group, rel_schema, rel_tblseq, rel_log_schema, rel_log_table, attname, atttypid, attlen, atttypmod
            FROM emaj.emaj_relation, pg_catalog.pg_attribute, pg_catalog.pg_class, pg_catalog.pg_namespace
            WHERE relnamespace = pg_namespace.oid AND nspname = rel_schema AND relname = rel_tblseq
              AND attrelid = pg_class.oid AND attnum > 0 AND attisdropped = false
              AND rel_group = ANY (v_groups) AND rel_kind = 'r'),
           cte_log_tables_columns AS (                -- log table's columns
          SELECT rel_group, rel_schema, rel_tblseq, rel_log_schema, rel_log_table, attname, atttypid, attlen, atttypmod
            FROM emaj.emaj_relation, pg_catalog.pg_attribute, pg_catalog.pg_class, pg_catalog.pg_namespace
            WHERE relnamespace = pg_namespace.oid AND nspname = rel_log_schema
              AND relname = rel_log_table
              AND attrelid = pg_class.oid AND attnum > 0 AND attisdropped = false AND attname NOT LIKE 'emaj%'
              AND rel_group = ANY (v_groups) AND rel_kind = 'r')
      SELECT DISTINCT rel_schema, rel_tblseq,
             'In group "' || rel_group || '", the structure of the application table "' ||
               rel_schema || '"."' || rel_tblseq || '" is not coherent with its log table ("' ||
             rel_log_schema || '"."' || rel_log_table || '").' AS msg
        FROM (
          (                                        -- application table's columns
          SELECT rel_group, rel_schema, rel_tblseq, rel_log_schema, rel_log_table, attname, atttypid, attlen, atttypmod
            FROM cte_app_tables_columns
          EXCEPT                                   -- minus log table's columns
          SELECT rel_group, rel_schema, rel_tblseq, rel_log_schema, rel_log_table, attname, atttypid, attlen, atttypmod
            FROM cte_log_tables_columns
          )
          UNION
          (                                         -- log table's columns
          SELECT rel_group, rel_schema, rel_tblseq, rel_log_schema, rel_log_table, attname, atttypid, attlen, atttypmod
            FROM cte_log_tables_columns
          EXCEPT                                    -- minus application table's columns
          SELECT rel_group, rel_schema, rel_tblseq, rel_log_schema, rel_log_table, attname, atttypid, attlen, atttypmod
            FROM cte_app_tables_columns
          )) AS t
        ORDER BY 1,2,3
    LOOP
      if v_onErrorStop THEN RAISE EXCEPTION '_verify_groups (6): % %',r_object.msg,v_hint; END IF;
      RETURN NEXT r_object;
    END LOOP;
    RETURN;
  END;
$_verify_groups$;

CREATE OR REPLACE FUNCTION emaj._check_fk_groups(v_groupNames TEXT[])
RETURNS VOID LANGUAGE plpgsql AS
$_check_fk_groups$
-- this function checks foreign key constraints for tables of a groups array.
-- tables from audit_only groups are ignored in this check because they will never be rolled back.
-- Input: group names array
  DECLARE
    r_fk                     RECORD;
  BEGIN
-- issue a warning if a table of the groups has a foreign key that references a table outside the groups
    FOR r_fk IN
      SELECT c.conname,r.rel_schema,r.rel_tblseq,nf.nspname,tf.relname
        FROM pg_catalog.pg_constraint c, pg_catalog.pg_namespace n, pg_catalog.pg_class t,
             pg_catalog.pg_namespace nf, pg_catalog.pg_class tf, emaj.emaj_relation r, emaj.emaj_group g
        WHERE contype = 'f'                                         -- FK constraints only
          AND c.conrelid  = t.oid  AND t.relnamespace  = n.oid      -- join for table and namespace
          AND c.confrelid = tf.oid AND tf.relnamespace = nf.oid     -- join for referenced table and namespace
          AND n.nspname = r.rel_schema AND t.relname = r.rel_tblseq -- join on emaj_relation table
          AND r.rel_group = g.group_name                            -- join on emaj_group table
          AND r.rel_group = ANY (v_groupNames)                      -- only tables of the selected groups
          AND g.group_is_rollbackable                               -- only tables from rollbackable groups
          AND NOT EXISTS                                            -- referenced table outside the groups
              (SELECT NULL FROM emaj.emaj_relation
                 WHERE rel_schema = nf.nspname AND rel_tblseq = tf.relname AND rel_group = ANY (v_groupNames))
        ORDER BY 1,2,3
      LOOP
      RAISE WARNING '_check_fk_groups: Foreign key "%", from table "%.%", references "%.%" that is outside groups (%).',
                r_fk.conname,r_fk.rel_schema,r_fk.rel_tblseq,r_fk.nspname,r_fk.relname,array_to_string(v_groupNames,',');
    END LOOP;
-- issue a warning if a table of the groups is referenced by a table outside the groups
    FOR r_fk IN
      SELECT c.conname,n.nspname,t.relname,r.rel_schema,r.rel_tblseq
        FROM pg_catalog.pg_constraint c, pg_catalog.pg_namespace n, pg_catalog.pg_class t,
             pg_catalog.pg_namespace nf, pg_catalog.pg_class tf, emaj.emaj_relation r, emaj.emaj_group g
        WHERE contype = 'f'                                           -- FK constraints only
          AND c.conrelid  = t.oid  AND t.relnamespace  = n.oid        -- join for table and namespace
          AND c.confrelid = tf.oid AND tf.relnamespace = nf.oid       -- join for referenced table and namespace
          AND nf.nspname = r.rel_schema AND tf.relname = r.rel_tblseq -- join with emaj_relation table
          AND r.rel_group = g.group_name                              -- join on emaj_group table
          AND r.rel_group = ANY (v_groupNames)                        -- only tables of the selected groups
          AND g.group_is_rollbackable                                 -- only tables from rollbackable groups
          AND NOT EXISTS                                              -- referenced table outside the groups
              (SELECT NULL FROM emaj.emaj_relation
                 WHERE rel_schema = n.nspname AND rel_tblseq = t.relname AND rel_group = ANY (v_groupNames))
        ORDER BY 1,2,3
      LOOP
      RAISE WARNING '_check_fk_groups: table "%.%" is referenced by foreign key "%" from table "%.%" that is outside groups (%).',
                r_fk.rel_schema,r_fk.rel_tblseq,r_fk.conname,r_fk.nspname,r_fk.relname,array_to_string(v_groupNames,',');
    END LOOP;
    RETURN;
  END;
$_check_fk_groups$;

CREATE OR REPLACE FUNCTION emaj._lock_groups(v_groupNames TEXT[], v_lockMode TEXT, v_multiGroup BOOLEAN)
RETURNS VOID LANGUAGE plpgsql AS
$_lock_groups$
-- This function locks all tables of a groups array.
-- The lock mode is provided by the calling function.
-- It only locks existing tables. It is calling function's responsability to handle cases when application tables are missing.
-- Input: array of group names, lock mode, flag indicating whether the function is called to processed several groups
  DECLARE
    v_nbRetry                SMALLINT = 0;
    v_nbTbl                  INT;
    v_ok                     BOOLEAN = false;
    v_fullTableName          TEXT;
    r_tblsq                  RECORD;
  BEGIN
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object)
      VALUES (CASE WHEN v_multiGroup THEN 'LOCK_GROUPS' ELSE 'LOCK_GROUP' END,'BEGIN', array_to_string(v_groupNames,','));
-- acquire lock on all tables
-- in case of deadlock, retry up to 5 times
    WHILE NOT v_ok AND v_nbRetry < 5 LOOP
      BEGIN
-- scan all existing tables of the groups
        v_nbTbl = 0;
        FOR r_tblsq IN
            SELECT rel_priority, rel_schema, rel_tblseq
               FROM emaj.emaj_relation, pg_catalog.pg_class, pg_catalog.pg_namespace
               WHERE rel_group = ANY (v_groupNames) AND rel_kind = 'r'
                 AND relnamespace = pg_namespace.oid AND nspname = rel_schema AND relname = rel_tblseq
               ORDER BY rel_priority, rel_schema, rel_tblseq
            LOOP
-- lock the table
          v_fullTableName = quote_ident(r_tblsq.rel_schema) || '.' || quote_ident(r_tblsq.rel_tblseq);
          EXECUTE 'LOCK TABLE ' || v_fullTableName || ' IN ' || v_lockMode || ' MODE';
          v_nbTbl = v_nbTbl + 1;
        END LOOP;
-- ok, all tables locked
        v_ok = true;
      EXCEPTION
        WHEN deadlock_detected THEN
          v_nbRetry = v_nbRetry + 1;
          RAISE NOTICE '_lock_groups: a deadlock has been trapped while locking tables of group "%".', v_groupNames;
      END;
    END LOOP;
    IF NOT v_ok THEN
      RAISE EXCEPTION '_lock_groups: too many (5) deadlocks encountered while locking tables of group "%".',v_groupNames;
    END IF;
-- insert end in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES (CASE WHEN v_multiGroup THEN 'LOCK_GROUPS' ELSE 'LOCK_GROUP' END, 'END', array_to_string(v_groupNames,','), v_nbTbl || ' tables locked, ' || v_nbRetry || ' deadlock(s)');
    RETURN;
  END;
$_lock_groups$;

CREATE OR REPLACE FUNCTION emaj.emaj_create_group(v_groupName TEXT, v_isRollbackable BOOLEAN DEFAULT true)
RETURNS INT LANGUAGE plpgsql AS
$emaj_create_group$
-- This function creates emaj objects for all tables of a group
-- It also creates the secondary E-Maj schemas when needed
-- Input: group name, boolean indicating wether the group is rollbackable or not (true by default)
-- Output: number of processed tables and sequences
  DECLARE
    v_timeId                 BIGINT;
    v_nbTbl                  INT = 0;
    v_nbSeq                  INT = 0;
    v_schemaPrefix           TEXT = 'emaj';
    v_defTsp                 TEXT;
    r_grpdef                 emaj.emaj_group_def%ROWTYPE;
    r_schema                 RECORD;
  BEGIN
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('CREATE_GROUP', 'BEGIN', v_groupName, CASE WHEN v_isRollbackable THEN 'rollbackable' ELSE 'audit_only' END);
-- check that the group name is valid
    IF v_groupName IS NULL OR v_groupName = ''THEN
      RAISE EXCEPTION 'emaj_create_group: group name can''t be NULL or empty.';
    END IF;
-- check the group is known in emaj_group_def table
    PERFORM 0 FROM emaj.emaj_group_def WHERE grpdef_group = v_groupName LIMIT 1;
    IF NOT FOUND THEN
       RAISE EXCEPTION 'emaj_create_group: group "%" is unknown in emaj_group_def table.', v_groupName;
    END IF;
-- check that the group is not yet recorded in emaj_group table
    PERFORM 0 FROM emaj.emaj_group WHERE group_name = v_groupName;
    IF FOUND THEN
      RAISE EXCEPTION 'emaj_create_group: group "%" is already created.', v_groupName;
    END IF;
-- performs various checks on the group's content described in the emaj_group_def table
    PERFORM emaj._check_group_content(v_groupName);
-- OK
-- get the time stamp of the operation
    SELECT emaj._set_time_stamp('C') INTO v_timeId;
-- insert group row in the emaj_group table
-- (The group_is_rlbk_protected boolean column is always initialized as not group_is_rollbackable)
    INSERT INTO emaj.emaj_group (group_name, group_is_logging, group_is_rollbackable, group_is_rlbk_protected, group_creation_time_id)
      VALUES (v_groupName, FALSE, v_isRollbackable, NOT v_isRollbackable, v_timeId);
-- look for new E-Maj secondary schemas to create
    FOR r_schema IN
      SELECT DISTINCT v_schemaPrefix || grpdef_log_schema_suffix AS log_schema FROM emaj.emaj_group_def
        WHERE grpdef_group = v_groupName
          AND grpdef_log_schema_suffix IS NOT NULL AND grpdef_log_schema_suffix <> ''
      EXCEPT
      SELECT DISTINCT rel_log_schema FROM emaj.emaj_relation
      ORDER BY 1
      LOOP
-- create the schema
      PERFORM emaj._create_log_schema(r_schema.log_schema);
-- and record the schema creation in emaj_hist table
      INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object)
        VALUES ('CREATE_GROUP','SCHEMA CREATED',quote_ident(r_schema.log_schema));
    END LOOP;
-- define the default tablespace, NULL if tspemaj tablespace doesn't exist
    SELECT 'tspemaj' INTO v_defTsp FROM pg_catalog.pg_tablespace WHERE spcname = 'tspemaj';
-- get and process all tables of the group (in priority order, NULLS being processed last)
    FOR r_grpdef IN
        SELECT emaj.emaj_group_def.*
          FROM emaj.emaj_group_def, pg_catalog.pg_class, pg_catalog.pg_namespace
          WHERE grpdef_group = v_groupName
            AND relnamespace = pg_namespace.oid
            AND nspname = grpdef_schema AND relname = grpdef_tblseq
            AND relkind = 'r'
          ORDER BY grpdef_priority, grpdef_schema, grpdef_tblseq
        LOOP
      PERFORM emaj._create_tbl(r_grpdef, v_groupName, v_isRollbackable, v_defTsp);
      v_nbTbl = v_nbTbl + 1;
    END LOOP;
-- get and process all sequences of the group (in priority order, NULLS being processed last)
    FOR r_grpdef IN
        SELECT emaj.emaj_group_def.*
          FROM emaj.emaj_group_def, pg_catalog.pg_class, pg_catalog.pg_namespace
          WHERE grpdef_group = v_groupName
            AND relnamespace = pg_namespace.oid
            AND nspname = grpdef_schema AND relname = grpdef_tblseq
            AND relkind = 'S'
          ORDER BY grpdef_priority, grpdef_schema, grpdef_tblseq
        LOOP
      PERFORM emaj._create_seq(r_grpdef, v_groupName);
      v_nbSeq = v_nbSeq + 1;
    END LOOP;
-- update tables and sequences counters in the emaj_group table
    UPDATE emaj.emaj_group SET group_nb_table = v_nbTbl, group_nb_sequence = v_nbSeq
      WHERE group_name = v_groupName;
-- check foreign keys with tables outside the group
    PERFORM emaj._check_fk_groups (array[v_groupName]);
-- insert end in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('CREATE_GROUP', 'END', v_groupName, v_nbTbl + v_nbSeq || ' tables/sequences processed');
    RETURN v_nbTbl + v_nbSeq;
  END;
$emaj_create_group$;

CREATE OR REPLACE FUNCTION emaj.emaj_comment_group(v_groupName TEXT, v_comment TEXT)
RETURNS VOID LANGUAGE plpgsql AS
$emaj_comment_group$
-- This function sets or modifies a comment on a group by updating the group_comment of the emaj_group table.
-- Input: group name, comment
--   To reset an existing comment for a group, the supplied comment can be NULL.
  DECLARE
  BEGIN
-- attempt to update the group_comment column from emaj_group table
    UPDATE emaj.emaj_group SET group_comment = v_comment WHERE group_name = v_groupName;
-- check that the group has been found
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_comment_group: group "%" has not been created.', v_groupName;
    END IF;
-- insert event in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_object)
      VALUES ('COMMENT_GROUP', v_groupName);
    RETURN;
  END;
$emaj_comment_group$;
COMMENT ON FUNCTION emaj.emaj_comment_group(TEXT,TEXT) IS
$$Sets a comment on an E-Maj group.$$;

CREATE OR REPLACE FUNCTION emaj._drop_group(v_groupName TEXT, v_isForced BOOLEAN)
RETURNS INT LANGUAGE plpgsql SECURITY DEFINER AS
$_drop_group$
-- This function effectively deletes the emaj objects for all tables of a group
-- It also drops secondary schemas that are not useful any more
-- Input: group name, and a boolean indicating whether the group's state has to be checked
-- Output: number of processed tables and sequences
-- The function is defined as SECURITY DEFINER so that secondary schemas can be dropped
  DECLARE
    v_groupIsLogging         BOOLEAN;
    v_event_trigger_array    TEXT[];
    v_nbTb                   INT = 0;
    v_schemaPrefix           TEXT = 'emaj';
    r_rel                    emaj.emaj_relation%ROWTYPE;
    r_schema                 RECORD;
  BEGIN
-- check that the group is recorded in emaj_group table
    SELECT group_is_logging INTO v_groupIsLogging
      FROM emaj.emaj_group WHERE group_name = v_groupName FOR UPDATE;
    IF NOT FOUND THEN
      RAISE EXCEPTION '_drop_group: group "%" has not been created.', v_groupName;
    END IF;
-- if the state of the group has to be checked,
    IF NOT v_isForced THEN
--   check that the group is not in LOGGING state
      IF v_groupIsLogging THEN
        RAISE EXCEPTION '_drop_group: The group "%" cannot be deleted because it is in LOGGING state.', v_groupName;
      END IF;
    END IF;
-- OK
-- disable event triggers that protect emaj components and keep in memory these triggers name
    SELECT emaj._disable_event_triggers() INTO v_event_trigger_array;
-- delete the emaj objets for each table of the group
    FOR r_rel IN
        SELECT * FROM emaj.emaj_relation
          WHERE rel_group = v_groupName ORDER BY rel_priority, rel_schema, rel_tblseq
        LOOP
      IF r_rel.rel_kind = 'r' THEN
-- if it is a table, delete the related emaj objects
        PERFORM emaj._drop_tbl(r_rel);
        ELSEIF r_rel.rel_kind = 'S' THEN
-- if it is a sequence, delete all related data from emaj_sequence table
          PERFORM emaj._drop_seq(r_rel);
      END IF;
      v_nbTb = v_nbTb + 1;
    END LOOP;
-- look for E-Maj secondary schemas to drop (i.e. not used by any other created group)
    FOR r_schema IN
      SELECT DISTINCT rel_log_schema FROM emaj.emaj_relation
        WHERE rel_group = v_groupName AND rel_log_schema <>  v_schemaPrefix
      EXCEPT
      SELECT DISTINCT rel_log_schema FROM emaj.emaj_relation
        WHERE rel_group <> v_groupName AND rel_log_schema <>  v_schemaPrefix
      ORDER BY 1
      LOOP
-- drop the schema
      PERFORM emaj._drop_log_schema(r_schema.rel_log_schema, v_isForced);
-- and record the schema suppression in emaj_hist table
      INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object)
        VALUES (CASE WHEN v_isForced THEN 'FORCE_DROP_GROUP' ELSE 'DROP_GROUP' END,'SCHEMA DROPPED',quote_ident(r_schema.rel_log_schema));
    END LOOP;
-- delete group row from the emaj_group table.
--   By cascade, it also deletes rows from emaj_relation and emaj_mark
    DELETE FROM emaj.emaj_group WHERE group_name = v_groupName;
-- enable previously disabled event triggers
    PERFORM emaj._enable_event_triggers(v_event_trigger_array);
    RETURN v_nbTb;
  END;
$_drop_group$;

CREATE OR REPLACE FUNCTION emaj.emaj_alter_group(v_groupName TEXT)
RETURNS INT LANGUAGE plpgsql AS
$emaj_alter_group$
-- This function alters a tables group.
-- It takes into account the changes recorded in the emaj_group_def table since the group has been created.
-- Executing emaj_alter_group() is equivalent to chaining emaj_drop_group() and emaj_create_group().
-- But only emaj objects that need to be dropped or created are processed.
-- Input: group name
-- Output: number of tables and sequences belonging to the group after the operation
  DECLARE
    v_emajSchema             TEXT = 'emaj';
    v_schemaPrefix           TEXT = 'emaj';
    v_nbCreate               INT = 0;
    v_nbDrop                 INT = 0;
    v_nbTbl                  INT;
    v_nbSeq                  INT;
    v_groupIsLogging         BOOLEAN;
    v_isRollbackable         BOOLEAN;
    v_timeId                 BIGINT;
    v_logSchema              TEXT;
    v_logSchemasToDrop       TEXT[];
    v_logSchemasToCreate     TEXT[];
    v_aLogSchema             TEXT;
    v_defTsp                 TEXT;
    v_event_trigger_array    TEXT[];
    r_grpdef                 emaj.emaj_group_def%ROWTYPE;
    r_rel                    emaj.emaj_relation%ROWTYPE;
    r_tblsq                  RECORD;
    r_schema                 RECORD;
  BEGIN
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object)
      VALUES ('ALTER_GROUP', 'BEGIN', v_groupName);
-- check that the group is recorded in emaj_group table
    SELECT group_is_logging, group_is_rollbackable INTO v_groupIsLogging, v_isRollbackable
      FROM emaj.emaj_group WHERE group_name = v_groupName FOR UPDATE;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_alter_group: group "%" has not been created.', v_groupName;
    END IF;
-- check that the group is not in LOGGING state
    IF v_groupIsLogging THEN
      RAISE EXCEPTION 'emaj_alter_group: The group "%" cannot be altered because it is in LOGGING state.', v_groupName;
    END IF;
-- check there are remaining rows for the group in emaj_group_def table
    PERFORM 0 FROM emaj.emaj_group_def WHERE grpdef_group = v_groupName LIMIT 1;
    IF NOT FOUND THEN
       RAISE EXCEPTION 'emaj_alter_group: Group "%" is unknown in emaj_group_def table.', v_groupName;
    END IF;
-- performs various checks on the group's content described in the emaj_group_def table
    PERFORM emaj._check_group_content(v_groupName);
-- OK
-- get the time stamp of the operation
    SELECT emaj._set_time_stamp('A') INTO v_timeId;
-- define the default tablespace, NULL if tspemaj tablespace doesn't exist
    SELECT 'tspemaj' INTO v_defTsp FROM pg_catalog.pg_tablespace WHERE spcname = 'tspemaj';
-- disable event triggers that protect emaj components and keep in memory these triggers name
    SELECT emaj._disable_event_triggers() INTO v_event_trigger_array;
-- We can now process:
--   - relations that do not belong to the tables group any more, by dropping their emaj components
--   - relations that continue to belong to the tables group but with different characteristics,
--     by first dropping their emaj components and letting the last step recreate them
--   - new relations in the tables group, by (re)creating their emaj components
--
-- build the list of secondary log schemas that will need to be dropped once obsolete log tables will be dropped
    SELECT array_agg(rel_log_schema) INTO v_logSchemasToDrop FROM (
      SELECT rel_log_schema FROM emaj.emaj_relation
        WHERE rel_group = v_groupName AND rel_log_schema <> v_emajSchema                -- secondary log schemas that currently exist for the group
      EXCEPT
      SELECT rel_log_schema FROM emaj.emaj_relation
        WHERE rel_group <> v_groupName                                                  -- minus those that exist for other groups
      EXCEPT
      SELECT v_schemaPrefix || grpdef_log_schema_suffix FROM emaj.emaj_group_def
        WHERE grpdef_group = v_groupName
          AND grpdef_log_schema_suffix IS NOT NULL AND grpdef_log_schema_suffix <> ''   -- minus those that will remain for the group
    ) AS t;
-- build the list of secondary log schemas that will need to be created before new log tables will be created
    SELECT array_agg(log_schema) INTO v_logSchemasToCreate FROM (
      SELECT DISTINCT v_schemaPrefix || grpdef_log_schema_suffix AS log_schema FROM emaj.emaj_group_def
        WHERE grpdef_group = v_groupName
          AND grpdef_log_schema_suffix IS NOT NULL AND grpdef_log_schema_suffix <> ''   -- secondary log schemas needed for the group
      EXCEPT
      SELECT DISTINCT rel_log_schema FROM emaj.emaj_relation                            -- minus those already created
      ORDER BY 1
    ) AS t;
-- list all relations that do not belong to the tables group any more
    FOR r_rel IN
      SELECT * FROM emaj.emaj_relation
        WHERE rel_group = v_groupName
          AND NOT EXISTS (
              SELECT NULL FROM emaj.emaj_group_def
                WHERE grpdef_schema = rel_schema AND grpdef_tblseq = rel_tblseq
                  AND grpdef_group = v_groupName)
      UNION
-- ... and all relations that are damaged or whose log table is not synchronised with them any more
      SELECT emaj.emaj_relation.*
        FROM (                                   -- all damaged or out of sync tables
          SELECT DISTINCT ver_schema, ver_tblseq FROM emaj._verify_groups(ARRAY[v_groupName], false)
             ) AS t, emaj.emaj_relation
        WHERE rel_schema = ver_schema AND rel_tblseq = ver_tblseq
      ORDER BY rel_priority, rel_schema, rel_tblseq
      LOOP
      CASE r_rel.rel_kind
        WHEN 'r' THEN
-- if it is a table, delete the related emaj objects
          PERFORM emaj._drop_tbl(r_rel);
        WHEN 'S' THEN
-- if it is a sequence, delete all related data from emaj_sequence table
          PERFORM emaj._drop_seq(r_rel);
      END CASE;
-- delete the related row in emaj_relation
      DELETE FROM emaj.emaj_relation WHERE rel_schema = r_rel.rel_schema AND rel_tblseq = r_rel.rel_tblseq;
      v_nbDrop = v_nbDrop + 1;
    END LOOP;
--
-- list relations that still belong to the tables group
    FOR r_tblsq IN
      SELECT rel_priority, rel_schema, rel_tblseq, rel_kind, rel_log_schema, rel_log_table, rel_log_dat_tsp, rel_log_idx_tsp,
             grpdef_priority, grpdef_schema, grpdef_tblseq, grpdef_log_schema_suffix, grpdef_emaj_names_prefix, grpdef_log_dat_tsp, grpdef_log_idx_tsp
        FROM emaj.emaj_relation, emaj.emaj_group_def
        WHERE rel_schema = grpdef_schema AND rel_tblseq = grpdef_tblseq
          AND rel_group = v_groupName
          AND grpdef_group = v_groupName
      ORDER BY rel_priority, rel_schema, rel_tblseq
      LOOP
-- now detect other changes that justify to drop and recreate the relation
-- detect if the log data tablespace in emaj_group_def has changed
      IF   (r_tblsq.rel_kind = 'r' AND coalesce(r_tblsq.rel_log_dat_tsp,'') <> coalesce(r_tblsq.grpdef_log_dat_tsp, v_defTsp,''))
        OR (r_tblsq.rel_kind = 'S' AND r_tblsq.grpdef_log_dat_tsp IS NOT NULL)
-- or if the log index tablespace in emaj_group_def has changed
        OR (r_tblsq.rel_kind = 'r' AND coalesce(r_tblsq.rel_log_idx_tsp,'') <> coalesce(r_tblsq.grpdef_log_idx_tsp, v_defTsp,''))
        OR (r_tblsq.rel_kind = 'S' AND r_tblsq.grpdef_log_idx_tsp IS NOT NULL)
-- or if the log schema in emaj_group_def has changed
        OR (r_tblsq.rel_kind = 'r' AND r_tblsq.rel_log_schema <> (v_schemaPrefix || coalesce(r_tblsq.grpdef_log_schema_suffix, '')))
        OR (r_tblsq.rel_kind = 'S' AND r_tblsq.grpdef_log_schema_suffix IS NOT NULL)
-- or if the emaj names prefix in emaj_group_def has changed (detected with the log table name)
        OR (r_tblsq.rel_kind = 'r' AND
            r_tblsq.rel_log_table <> (coalesce(r_tblsq.grpdef_emaj_names_prefix, r_tblsq.grpdef_schema || '_' || r_tblsq.grpdef_tblseq) || '_log'))
        OR (r_tblsq.rel_kind = 'S' AND r_tblsq.grpdef_emaj_names_prefix IS NOT NULL) THEN
-- then drop the relation (it will be recreated later)
-- get the related row in emaj_relation
        SELECT * FROM emaj.emaj_relation WHERE rel_schema = r_tblsq.rel_schema AND rel_tblseq = r_tblsq.rel_tblseq INTO r_rel;
        IF r_tblsq.rel_kind = 'r' THEN
-- if it is a table, delete the related emaj objects
          PERFORM emaj._drop_tbl (r_rel);
        ELSEIF r_tblsq.rel_kind = 'S' THEN
-- if it is a sequence, delete all related data from emaj_sequence table
          PERFORM emaj._drop_seq (r_rel);
        END IF;
-- delete the related row in emaj_relation
        DELETE FROM emaj.emaj_relation WHERE rel_schema = r_tblsq.grpdef_schema AND rel_tblseq = r_tblsq.grpdef_tblseq;
        v_nbDrop = v_nbDrop + 1;
-- other case ?
-- has the priority changed in emaj_group_def ? If yes, just report the change into emaj_relation
      ELSEIF (r_tblsq.rel_priority IS NULL AND r_tblsq.grpdef_priority IS NOT NULL) OR
             (r_tblsq.rel_priority IS NOT NULL AND r_tblsq.grpdef_priority IS NULL) OR
             (r_tblsq.rel_priority <> r_tblsq.grpdef_priority) THEN
        UPDATE emaj.emaj_relation SET rel_priority = r_tblsq.grpdef_priority
          WHERE rel_schema = r_tblsq.grpdef_schema AND rel_tblseq = r_tblsq.grpdef_tblseq;
      END IF;
    END LOOP;
--
-- cleanup all remaining log tables
    PERFORM emaj._reset_group(v_groupName);
-- drop useless log schemas, using the list of schemas to drop built previously
    IF v_logSchemasToDrop IS NOT NULL THEN
      FOREACH v_aLogSchema IN ARRAY v_logSchemasToDrop LOOP
--   drop the log schema
        PERFORM emaj._drop_log_schema(v_aLogSchema, false);
--   and record the schema drop in emaj_hist table
        INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object)
          VALUES ('ALTER_GROUP','SCHEMA DROPPED',quote_ident(v_aLogSchema));
      END LOOP;
    END IF;
-- create new log schemas, using the list of potential schemas to create built previously
    IF v_logSchemasToCreate IS NOT NULL THEN
      FOREACH v_aLogSchema IN ARRAY v_logSchemasToCreate LOOP
--   create the schema
        PERFORM emaj._create_log_schema(v_aLogSchema);
--   and record the schema creation in emaj_hist table
        INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object)
          VALUES ('ALTER_GROUP','SCHEMA CREATED',quote_ident(v_aLogSchema));
      END LOOP;
    END IF;
--
-- get and process new tables in the tables group (really new or intentionaly dropped in the preceeding steps)
    FOR r_grpdef IN
      SELECT emaj.emaj_group_def.*
        FROM emaj.emaj_group_def, pg_catalog.pg_class, pg_catalog.pg_namespace
        WHERE grpdef_group = v_groupName
          AND NOT EXISTS (
              SELECT NULL FROM emaj.emaj_relation
                WHERE rel_schema = grpdef_schema AND rel_tblseq = grpdef_tblseq
                  AND rel_group = v_groupName)
          AND relnamespace = pg_namespace.oid AND nspname = grpdef_schema AND relname = grpdef_tblseq
          AND relkind = 'r'
      ORDER BY grpdef_priority, grpdef_schema, grpdef_tblseq
      LOOP
      PERFORM emaj._create_tbl(r_grpdef, v_groupName, v_isRollbackable, v_defTsp);
      v_nbCreate = v_nbCreate + 1;
    END LOOP;
-- get and process new sequences in the tables group (really new or intentionaly dropped in the preceeding steps)
    FOR r_grpdef IN
      SELECT emaj.emaj_group_def.*
        FROM emaj.emaj_group_def, pg_catalog.pg_class, pg_catalog.pg_namespace
        WHERE grpdef_group = v_groupName
          AND NOT EXISTS (
              SELECT NULL FROM emaj.emaj_relation
                WHERE rel_schema = grpdef_schema AND rel_tblseq = grpdef_tblseq
                  AND rel_group = v_groupName)
          AND relnamespace = pg_namespace.oid AND nspname = grpdef_schema AND relname = grpdef_tblseq
          AND relkind = 'S'
      ORDER BY grpdef_priority, grpdef_schema, grpdef_tblseq
      LOOP
      PERFORM emaj._create_seq(r_grpdef, v_groupName);
      v_nbCreate = v_nbCreate + 1;
    END LOOP;
-- update tables and sequences counters and the last alter timestamp in the emaj_group table
    SELECT count(*) INTO v_nbTbl FROM emaj.emaj_relation WHERE rel_group = v_groupName AND rel_kind = 'r';
    SELECT count(*) INTO v_nbSeq FROM emaj.emaj_relation WHERE rel_group = v_groupName AND rel_kind = 'S';
    UPDATE emaj.emaj_group SET group_last_alter_time_id = v_timeId, group_nb_table = v_nbTbl, group_nb_sequence = v_nbSeq
      WHERE group_name = v_groupName;
-- delete old marks of the tables group from emaj_mark
    DELETE FROM emaj.emaj_mark WHERE mark_group = v_groupName;
-- enable previously disabled event triggers
    PERFORM emaj._enable_event_triggers(v_event_trigger_array);
-- check foreign keys with tables outside the group
    PERFORM emaj._check_fk_groups(array[v_groupName]);
-- insert end in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('ALTER_GROUP', 'END', v_groupName, v_nbDrop || ' dropped relations and ' || v_nbCreate || ' (re)created relations');
    RETURN v_nbTbl + v_nbSeq;
  END;
$emaj_alter_group$;
COMMENT ON FUNCTION emaj.emaj_alter_group(TEXT) IS
$$Alter an E-Maj group.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_start_group(v_groupName TEXT, v_mark TEXT DEFAULT 'START_%', v_resetLog BOOLEAN DEFAULT true)
RETURNS INT LANGUAGE plpgsql AS
$emaj_start_group$
-- This function activates the log triggers of all the tables for a group and set a first mark
-- It may reset log tables.
-- Input: group name,
--        name of the mark to set
--          '%' wild characters in mark name are transformed into a characters sequence built from the current timestamp
--          if omitted or if null or '', the mark is set to 'START_%', % representing the current timestamp
--        boolean indicating whether the log tables of the group must be reset, true by default.
-- Output: number of processed tables and sequences
  DECLARE
    v_nbTblSeq               INT;
  BEGIN
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('START_GROUP', 'BEGIN', v_groupName, CASE WHEN v_resetLog THEN 'With log reset' ELSE 'Without log reset' END);
-- call the common _start_groups function
    SELECT emaj._start_groups(array[v_groupName], v_mark, false, v_resetLog) INTO v_nbTblSeq;
-- insert end in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('START_GROUP', 'END', v_groupName, v_nbTblSeq || ' tables/sequences processed');
    RETURN v_nbTblSeq;
  END;
$emaj_start_group$;
COMMENT ON FUNCTION emaj.emaj_start_group(TEXT,TEXT,BOOLEAN) IS
$$Starts an E-Maj group.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_start_groups(v_groupNames TEXT[], v_mark TEXT DEFAULT 'START_%', v_resetLog BOOLEAN DEFAULT true)
RETURNS INT LANGUAGE plpgsql AS
$emaj_start_groups$
-- This function activates the log triggers of all the tables for a groups array and set a first mark
-- Input: array of group names,
--        name of the mark to set (if omitted, START_<current timestamp>)
--          '%' wild characters in mark name are transformed into a characters sequence built from the current timestamp
--          if omitted or if null or '', the mark is set to 'START_%', % representing the current timestamp
--        boolean indicating whether the log tables of the group must be reset, true by default.
-- Output: total number of processed tables and sequences
  DECLARE
    v_nbTblSeq               INT;
  BEGIN
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('START_GROUPS', 'BEGIN', array_to_string(v_groupNames,','), CASE WHEN v_resetLog THEN 'With log reset' ELSE 'Without log reset' END);
-- call the common _start_groups function
    SELECT emaj._start_groups(emaj._check_names_array(v_groupNames,'group'), v_mark, true, v_resetLog) INTO v_nbTblSeq;
-- insert end in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('START_GROUPS', 'END', array_to_string(v_groupNames,','), v_nbTblSeq || ' tables/sequences processed');
    RETURN v_nbTblSeq;
  END;
$emaj_start_groups$;

CREATE OR REPLACE FUNCTION emaj._start_groups(v_groupNames TEXT[], v_mark TEXT, v_multiGroup BOOLEAN, v_resetLog BOOLEAN)
RETURNS INT LANGUAGE plpgsql SECURITY DEFINER AS
$_start_groups$
-- This function activates the log triggers of all the tables for one or several groups and set a first mark
-- It also delete oldest rows in emaj_hist table
-- Input: array of group names, name of the mark to set, boolean indicating whether the function is called by a multi group function, boolean indicating whether the function must reset the group at start time
-- Output: number of processed tables
-- The function is defined as SECURITY DEFINER so that emaj_adm role can use it even if he is not the owner of application tables and sequences.
  DECLARE
    v_aGroupName             TEXT;
    v_groupIsLogging         BOOLEAN;
    v_nbTb                   INT = 0;
    v_markName               TEXT;
    v_fullTableName          TEXT;
    r_tblsq                  RECORD;
  BEGIN
-- purge the emaj history, if needed
    PERFORM emaj._purge_hist();
-- if the group names array is null, immediately return 0
    IF v_groupNames IS NULL THEN
      RETURN 0;
    END IF;
-- check that each group is recorded in emaj_group table
    FOREACH v_aGroupName IN ARRAY v_groupNames LOOP
      SELECT group_is_logging INTO v_groupIsLogging
        FROM emaj.emaj_group WHERE group_name = v_aGroupName FOR UPDATE;
      IF NOT FOUND THEN
        RAISE EXCEPTION '_start_groups: group "%" has not been created.', v_aGroupName;
      END IF;
-- ... and is not in LOGGING state
      IF v_groupIsLogging THEN
        RAISE EXCEPTION '_start_groups: The group "%" cannot be started because it is in LOGGING state. An emaj_stop_group function must be previously executed.', v_aGroupName;
      END IF;
    END LOOP;
-- check that no group is damaged
    PERFORM 0 FROM emaj._verify_groups(v_groupNames, true);
-- check foreign keys with tables outside the group
    PERFORM emaj._check_fk_groups(v_groupNames);
-- if requested by the user, call the emaj_reset_group() function to erase remaining traces from previous logs
    if v_resetLog THEN
      PERFORM emaj._reset_group(unnest(v_groupNames));
    END IF;
-- check and process the supplied mark name
    IF v_mark IS NULL OR v_mark = '' THEN
      v_mark = 'START_%';
    END IF;
    SELECT emaj._check_new_mark(v_mark, v_groupNames) INTO v_markName;
-- OK, lock all tables to get a stable point
--   one sets the locks at the beginning of the operation (rather than let the ALTER TABLE statements set their own locks) to decrease the risk of deadlock.
--   the requested lock level is based on the lock level of the future ALTER TABLE, which depends on the postgres version.
    IF emaj._pg_version_num() >= 90500 THEN
      PERFORM emaj._lock_groups(v_groupNames,'SHARE ROW EXCLUSIVE',v_multiGroup);
    ELSE
      PERFORM emaj._lock_groups(v_groupNames,'ACCESS EXCLUSIVE',v_multiGroup);
    END IF;
-- enable all log triggers for the groups
    v_nbTb = 0;
-- for each relation of the group,
    FOR r_tblsq IN
       SELECT rel_priority, rel_schema, rel_tblseq, rel_kind FROM emaj.emaj_relation
         WHERE rel_group = ANY (v_groupNames) ORDER BY rel_priority, rel_schema, rel_tblseq
       LOOP
      CASE r_tblsq.rel_kind
        WHEN 'r' THEN
-- if it is a table, enable the emaj log and truncate triggers
          v_fullTableName  = quote_ident(r_tblsq.rel_schema) || '.' || quote_ident(r_tblsq.rel_tblseq);
          EXECUTE 'ALTER TABLE ' || v_fullTableName || ' ENABLE TRIGGER emaj_log_trg, ENABLE TRIGGER emaj_trunc_trg';
        WHEN 'S' THEN
-- if it is a sequence, nothing to do
      END CASE;
      v_nbTb = v_nbTb + 1;
    END LOOP;
-- update the state of the group row from the emaj_group table
    UPDATE emaj.emaj_group SET group_is_logging = TRUE WHERE group_name = ANY (v_groupNames);
-- Set the first mark for each group
    PERFORM emaj._set_mark_groups(v_groupNames, v_markName, v_multiGroup, true);
--
    RETURN v_nbTb;
  END;
$_start_groups$;

CREATE OR REPLACE FUNCTION emaj.emaj_stop_group(v_groupName TEXT, v_mark TEXT DEFAULT 'STOP_%')
RETURNS INT LANGUAGE plpgsql AS
$emaj_stop_group$
-- This function de-activates the log triggers of all the tables for a group.
-- Execute several emaj_stop_group functions for the same group doesn't produce any error.
-- Input: group name
--        name of the mark to set (if omitted, STOP_<current timestamp>)
--          '%' wild characters in mark name are transformed into a characters sequence built from the current timestamp
--          if omitted or if null or '', the mark is set to 'STOP_%', % representing the current timestamp
-- Output: number of processed tables and sequences
  DECLARE
    v_nbTblSeq               INT;
  BEGIN
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object)
      VALUES ('STOP_GROUP', 'BEGIN', v_groupName);
-- call the common _stop_groups function
    SELECT emaj._stop_groups(array[v_groupName], v_mark, false, false) INTO v_nbTblSeq;
-- insert end in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('STOP_GROUP', 'END', v_groupName, v_nbTblSeq || ' tables/sequences processed');
    RETURN v_nbTblSeq;
  END;
$emaj_stop_group$;
COMMENT ON FUNCTION emaj.emaj_stop_group(TEXT,TEXT) IS
$$Stops an E-Maj group.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_stop_groups(v_groupNames TEXT[], v_mark TEXT DEFAULT 'STOP_%')
RETURNS INT LANGUAGE plpgsql AS
$emaj_stop_groups$
-- This function de-activates the log triggers of all the tables for a groups array.
-- Groups already not in LOGGING state are simply not processed.
-- Input: array of group names, stop mark name to set (by default, STOP_<current timestamp>)
-- Output: number of processed tables and sequences
  DECLARE
    v_nbTblSeq               INT;
  BEGIN
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object)
      VALUES ('STOP_GROUPS', 'BEGIN', array_to_string(v_groupNames,','));
-- call the common _stop_groups function
    SELECT emaj._stop_groups(emaj._check_names_array(v_groupNames,'group'), v_mark, true, false) INTO v_nbTblSeq;
-- insert end in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('STOP_GROUPS', 'END', array_to_string(v_groupNames,','), v_nbTblSeq || ' tables/sequences processed');
    RETURN v_nbTblSeq;
  END;
$emaj_stop_groups$;

CREATE OR REPLACE FUNCTION emaj._stop_groups(v_groupNames TEXT[], v_mark TEXT, v_multiGroup BOOLEAN, v_isForced BOOLEAN)
RETURNS INT LANGUAGE plpgsql SECURITY DEFINER AS
$_stop_groups$
-- This function effectively de-activates the log triggers of all the tables for a group.
-- Input: array of group names, a mark name to set, and a boolean indicating if the function is called by a multi group function
-- Output: number of processed tables and sequences
-- The function is defined as SECURITY DEFINER so that emaj_adm role can use it even if he is not the owner of application tables and sequences.
  DECLARE
    v_validGroupNames        TEXT[];
    v_aGroupName             TEXT;
    v_groupIsLogging         BOOLEAN;
    v_nbTb                   INT = 0;
    v_markName               TEXT;
    v_fullTableName          TEXT;
    r_schema                 RECORD;
    r_tblsq                  RECORD;
  BEGIN
-- if the group names array is null, immediately return 0
    IF v_groupNames IS NULL THEN
      RETURN 0;
    END IF;
-- for each group of the array,
    FOREACH v_aGroupName IN ARRAY v_groupNames LOOP
-- ... check that the group is recorded in emaj_group table
      SELECT group_is_logging INTO v_groupIsLogging
        FROM emaj.emaj_group WHERE group_name = v_aGroupName FOR UPDATE;
      IF NOT FOUND THEN
        RAISE EXCEPTION '_stop_groups: group "%" has not been created.', v_aGroupName;
      END IF;
-- ... check that the group is in LOGGING state
      IF NOT v_groupIsLogging THEN
        RAISE WARNING '_stop_groups: Group "%" cannot be stopped because it is not in LOGGING state.', v_aGroupName;
      ELSE
-- ... if OK, add the group into the array of groups to process
        v_validGroupNames = v_validGroupNames || array[v_aGroupName];
      END IF;
    END LOOP;
-- check and process the supplied mark name (except if the function is called by emaj_force_stop_group())
    IF v_mark IS NULL OR v_mark = '' THEN
      v_mark = 'STOP_%';
    END IF;
    IF NOT v_isForced THEN
      SELECT emaj._check_new_mark(v_mark, v_groupNames) INTO v_markName;
    END IF;
--
    IF v_validGroupNames IS NOT NULL THEN
-- OK (no error detected and at least one group in logging state)
-- lock all tables to get a stable point
--   one sets the locks at the beginning of the operation (rather than let the ALTER TABLE statements set their own locks) to decrease the risk of deadlock.
--   the requested lock level is based on the lock level of the future ALTER TABLE, which depends on the postgres version.
      IF emaj._pg_version_num() >= 90500 THEN
        PERFORM emaj._lock_groups(v_validGroupNames,'SHARE ROW EXCLUSIVE',v_multiGroup);
      ELSE
        PERFORM emaj._lock_groups(v_validGroupNames,'ACCESS EXCLUSIVE',v_multiGroup);
      END IF;
-- verify that all application schemas for the groups still exists
      FOR r_schema IN
          SELECT DISTINCT rel_schema FROM emaj.emaj_relation
            WHERE rel_group = ANY (v_validGroupNames)
              AND NOT EXISTS (SELECT nspname FROM pg_catalog.pg_namespace WHERE nspname = rel_schema)
            ORDER BY rel_schema
        LOOP
        IF v_isForced THEN
          RAISE WARNING '_stop_groups: Schema "%" does not exist any more.', r_schema.rel_schema;
        ELSE
          RAISE EXCEPTION '_stop_groups: Schema "%" does not exist any more.', r_schema.rel_schema;
        END IF;
      END LOOP;
-- for each relation of the groups to process,
      FOR r_tblsq IN
          SELECT rel_priority, rel_schema, rel_tblseq, rel_kind FROM emaj.emaj_relation
            WHERE rel_group = ANY (v_validGroupNames) ORDER BY rel_priority, rel_schema, rel_tblseq
        LOOP
        CASE r_tblsq.rel_kind
          WHEN 'r' THEN
-- if it is a table, check the table still exists
            PERFORM 1 FROM pg_catalog.pg_namespace, pg_catalog.pg_class
              WHERE  relnamespace = pg_namespace.oid AND nspname = r_tblsq.rel_schema AND relname = r_tblsq.rel_tblseq;
            IF NOT FOUND THEN
              IF v_isForced THEN
                RAISE WARNING '_stop_groups: Table "%.%" does not exist any more.', r_tblsq.rel_schema, r_tblsq.rel_tblseq;
              ELSE
                RAISE EXCEPTION '_stop_groups: Table "%.%" does not exist any more.', r_tblsq.rel_schema, r_tblsq.rel_tblseq;
              END IF;
            ELSE
-- and disable the emaj log and truncate triggers
--   errors are captured so that emaj_force_stop_group() can be silently executed
              v_fullTableName  = quote_ident(r_tblsq.rel_schema) || '.' || quote_ident(r_tblsq.rel_tblseq);
              BEGIN
                EXECUTE 'ALTER TABLE ' || v_fullTableName || ' DISABLE TRIGGER emaj_log_trg';
              EXCEPTION
                WHEN undefined_object THEN
                  IF v_isForced THEN
                    RAISE WARNING '_stop_groups: Log trigger "emaj_log_trg" on table "%.%" does not exist any more.', r_tblsq.rel_schema, r_tblsq.rel_tblseq;
                  ELSE
                    RAISE EXCEPTION '_stop_groups: Log trigger "emaj_log_trg" on table "%.%" does not exist any more.', r_tblsq.rel_schema, r_tblsq.rel_tblseq;
                  END IF;
              END;
              BEGIN
                EXECUTE 'ALTER TABLE ' || v_fullTableName || ' DISABLE TRIGGER emaj_trunc_trg';
              EXCEPTION
                WHEN undefined_object THEN
                  IF v_isForced THEN
                    RAISE WARNING '_stop_groups: Truncate trigger "emaj_trunc_trg" on table "%.%" does not exist any more.', r_tblsq.rel_schema, r_tblsq.rel_tblseq;
                  ELSE
                    RAISE EXCEPTION '_stop_groups: Truncate trigger "emaj_trunc_trg" on table "%.%" does not exist any more.', r_tblsq.rel_schema, r_tblsq.rel_tblseq;
                  END IF;
              END;
            END IF;
          WHEN 'S' THEN
-- if it is a sequence, nothing to do
        END CASE;
        v_nbTb = v_nbTb + 1;
      END LOOP;
      IF NOT v_isForced THEN
-- if the function is not called by emaj_force_stop_group(), set the stop mark for each group
        PERFORM emaj._set_mark_groups(v_validGroupNames, v_markName, v_multiGroup, true);
-- and set the number of log rows to 0 for these marks
        UPDATE emaj.emaj_mark m SET mark_log_rows_before_next = 0
          WHERE mark_group = ANY (v_validGroupNames)
            AND (mark_group, mark_id) IN                        -- select only last mark of each concerned group
                (SELECT mark_group, MAX(mark_id) FROM emaj.emaj_mark
                 WHERE mark_group = ANY (v_validGroupNames) AND NOT mark_is_deleted GROUP BY mark_group);
      END IF;
-- set all marks for the groups from the emaj_mark table as 'DELETED' to avoid any further rollback and remove protection if any
      UPDATE emaj.emaj_mark SET mark_is_deleted = TRUE, mark_is_rlbk_protected = FALSE
        WHERE mark_group = ANY (v_validGroupNames) AND NOT mark_is_deleted;
-- update the state of the groups rows from the emaj_group table (the rollback protection of rollbackable groups is reset)
      UPDATE emaj.emaj_group SET group_is_logging = FALSE, group_is_rlbk_protected = NOT group_is_rollbackable
        WHERE group_name = ANY (v_validGroupNames);
    END IF;
    RETURN v_nbTb;
  END;
$_stop_groups$;

CREATE OR REPLACE FUNCTION emaj.emaj_protect_group(v_groupName TEXT)
RETURNS INT LANGUAGE plpgsql AS
$emaj_protect_group$
-- This function sets a protection on a group against accidental rollback.
-- Input: group name
-- Output: 1 if successful, 0 if the group was already in protected state
  DECLARE
    v_groupIsRollbackable    BOOLEAN;
    v_groupIsLogging         BOOLEAN;
    v_groupIsProtected       BOOLEAN;
    v_status                 INT;
  BEGIN
-- check that the group is recorded in emaj_group table
    SELECT group_is_rollbackable, group_is_logging, group_is_rlbk_protected INTO v_groupIsRollbackable, v_groupIsLogging, v_groupIsProtected
      FROM emaj.emaj_group WHERE group_name = v_groupName FOR UPDATE;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_protect_group: group % has not been created.', v_groupName;
    END IF;
-- check that the group is ROLLBACKABLE
    IF NOT v_groupIsRollbackable THEN
      RAISE EXCEPTION 'emaj_protect_group: The group "%" cannot be protected because it is an AUDIT_ONLY group.', v_groupName;
    END IF;
-- check that the group is not in LOGGING state
    IF NOT v_groupIsLogging THEN
      RAISE EXCEPTION 'emaj_protect_group: The group "%" cannot be protected because it is not in LOGGING state.', v_groupName;
    END IF;
-- OK, set the protection
    IF v_groupIsProtected THEN
      v_status = 0;
    ELSE
      UPDATE emaj.emaj_group SET group_is_rlbk_protected = TRUE WHERE group_name = v_groupName;
      v_status = 1;
    END IF;
-- insert event in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_object, hist_wording)
      VALUES ('PROTECT_GROUP', v_groupName, 'Status ' || v_status);
    RETURN v_status;
  END;
$emaj_protect_group$;
COMMENT ON FUNCTION emaj.emaj_protect_group(TEXT) IS
$$Sets a protection against a rollback on an E-Maj group.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_unprotect_group(v_groupName TEXT)
RETURNS INT LANGUAGE plpgsql AS
$emaj_unprotect_group$
-- This function unsets a protection on a group against accidental rollback.
-- Input: group name
-- Output: 1 if successful, 0 if the group was not already in protected state
  DECLARE
    v_groupIsRollbackable    BOOLEAN;
    v_groupIsProtected       BOOLEAN;
    v_status                 INT;
  BEGIN
-- check that the group is recorded in emaj_group table
    SELECT group_is_rollbackable, group_is_rlbk_protected INTO v_groupIsRollbackable, v_groupIsProtected
      FROM emaj.emaj_group WHERE group_name = v_groupName FOR UPDATE;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_unprotect_group: group "%" has not been created.', v_groupName;
    END IF;
-- check that the group is ROLLBACKABLE
    IF NOT v_groupIsRollbackable THEN
      RAISE EXCEPTION 'emaj_unprotect_group: The group "%" cannot be unprotected because it is an AUDIT_ONLY group.', v_groupName;
    END IF;
-- OK, unset the protection
    IF NOT v_groupIsProtected THEN
      v_status = 0;
    ELSE
      UPDATE emaj.emaj_group SET group_is_rlbk_protected = FALSE WHERE group_name = v_groupName;
      v_status = 1;
    END IF;
-- insert event in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_object, hist_wording)
      VALUES ('UNPROTECT_GROUP', v_groupName, 'Status ' || v_status);
    RETURN v_status;
  END;
$emaj_unprotect_group$;
COMMENT ON FUNCTION emaj.emaj_unprotect_group(TEXT) IS
$$Unsets a protection against a rollback on an E-Maj group.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_set_mark_group(v_groupName TEXT, v_mark TEXT DEFAULT NULL)
RETURNS INT LANGUAGE plpgsql AS
$emaj_set_mark_group$
-- This function inserts a mark in the emaj_mark table and takes an image of the sequences definitions for the group
-- Input: group name, mark to set
--        '%' wild characters in mark name are transformed into a characters sequence built from the current timestamp
--        if omitted or if null or '', the mark is set to 'MARK_%', % representing the current timestamp
-- Output: number of processed tables and sequences
  DECLARE
    v_groupIsLogging         BOOLEAN;
    v_markName               TEXT;
    v_nbTb                   INT;
  BEGIN
-- insert begin into the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('SET_MARK_GROUP', 'BEGIN', v_groupName, v_markName);
-- check that the group is recorded in emaj_group table
-- (the SELECT is coded FOR UPDATE to lock the accessed group, avoiding any operation on this group at the same time)
    SELECT group_is_logging INTO v_groupIsLogging
      FROM emaj.emaj_group WHERE group_name = v_groupName FOR UPDATE;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_set_mark_group: group "%" has not been created.', v_groupName;
    END IF;
-- check that the group is in LOGGING state
    IF NOT v_groupIsLogging THEN
      RAISE EXCEPTION 'emaj_set_mark_group: A mark cannot be set for group "%" because it is not in LOGGING state. An emaj_start_group function must be previously executed.', v_groupName;
    END IF;
-- check if the emaj group is OK
    PERFORM 0 FROM emaj._verify_groups(array[v_groupName], true);
-- check and process the supplied mark name
    SELECT emaj._check_new_mark(v_mark, array[v_groupName]) INTO v_markName;
-- OK, lock all tables to get a stable point ...
-- use a ROW EXCLUSIVE lock mode, preventing for a transaction currently updating data, but not conflicting with simple read access or vacuum operation.
    PERFORM emaj._lock_groups(array[v_groupName],'ROW EXCLUSIVE',false);
-- Effectively set the mark using the internal _set_mark_groups() function
    SELECT emaj._set_mark_groups(array[v_groupName], v_markName, false, false) INTO v_nbTb;
-- insert end into the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('SET_MARK_GROUP', 'END', v_groupName, v_markName);
--
    RETURN v_nbTb;
  END;
$emaj_set_mark_group$;
COMMENT ON FUNCTION emaj.emaj_set_mark_group(TEXT,TEXT) IS
$$Sets a mark on an E-Maj group.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_set_mark_groups(v_groupNames TEXT[], v_mark TEXT DEFAULT NULL)
RETURNS INT LANGUAGE plpgsql AS
$emaj_set_mark_groups$
-- This function inserts a mark in the emaj_mark table and takes an image of the sequences definitions for several groups at a time
-- Input: array of group names, mark to set
--        '%' wild characters in mark name are transformed into a characters sequence built from the current timestamp
--        if omitted or if null or '', the mark is set to 'MARK_%', % representing the current timestamp
-- Output: number of processed tables and sequences
  DECLARE
    v_validGroupNames        TEXT[];
    v_aGroupName             TEXT;
    v_groupIsLogging         BOOLEAN;
    v_markName               TEXT;
    v_nbTb                   INT;
  BEGIN
-- validate the group names array
    v_validGroupNames=emaj._check_names_array(v_groupNames,'group');
-- if the group names array is null, immediately return 0
    IF v_validGroupNames IS NULL THEN
      INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
        VALUES ('SET_MARK_GROUPS', 'BEGIN', NULL, v_mark);
      INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
        VALUES ('SET_MARK_GROUPS', 'END', NULL, v_mark);
      RETURN 0;
    END IF;
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('SET_MARK_GROUPS', 'BEGIN', array_to_string(v_groupNames,','), v_mark);
-- for each group...
    FOREACH v_aGroupName IN ARRAY v_validGroupNames LOOP
-- ... check that the group is recorded in emaj_group table
-- (the SELECT is coded FOR UPDATE to lock the accessed group, avoiding any operation on this group at the same time)
      SELECT group_is_logging INTO v_groupIsLogging
        FROM emaj.emaj_group WHERE group_name = v_aGroupName FOR UPDATE;
      IF NOT FOUND THEN
        RAISE EXCEPTION 'emaj_set_mark_groups: group "%" has not been created.', v_aGroupName;
      END IF;
-- ... check that the group is in LOGGING state
      IF NOT v_groupIsLogging THEN
        RAISE EXCEPTION 'emaj_set_mark_groups: A mark cannot be set for group "%" because it is not in LOGGING state. An emaj_start_group function must be previously executed.', v_aGroupName;
      END IF;
    END LOOP;
-- check that no group is damaged
    PERFORM 0 FROM emaj._verify_groups(v_validGroupNames, true);
-- check and process the supplied mark name
    SELECT emaj._check_new_mark(v_mark, v_validGroupNames) INTO v_markName;
-- OK, lock all tables to get a stable point ...
-- use a ROW EXCLUSIVE lock mode, preventing for a transaction currently updating data, but not conflicting with simple read access or vacuum operation.
    PERFORM emaj._lock_groups(v_validGroupNames,'ROW EXCLUSIVE',true);
-- Effectively set the mark using the internal _set_mark_groups() function
    SELECT emaj._set_mark_groups(v_validGroupNames, v_markName, true, false) INTO v_nbTb;
-- insert end into the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('SET_MARK_GROUPS', 'END', array_to_string(v_groupNames,','), v_mark);
--
    RETURN v_nbTb;
  END;
$emaj_set_mark_groups$;
COMMENT ON FUNCTION emaj.emaj_set_mark_groups(TEXT[],TEXT) IS
$$Sets a mark on several E-Maj groups.$$;

CREATE OR REPLACE FUNCTION emaj._set_mark_groups(v_groupNames TEXT[], v_mark TEXT, v_multiGroup BOOLEAN, v_eventToRecord BOOLEAN, v_loggedRlbkTargetMark TEXT DEFAULT NULL, v_timeId BIGINT DEFAULT NULL)
RETURNS INT LANGUAGE plpgsql AS
$_set_mark_groups$
-- This function effectively inserts a mark in the emaj_mark table and takes an image of the sequences definitions for the array of groups.
-- It also updates the previous mark of each group to setup the mark_log_rows_before_next column with the number of rows recorded into all log tables between this previous mark and the new mark.
-- It is called by emaj_set_mark_group and emaj_set_mark_groups functions but also by other functions that set internal marks, like functions that start or rollback groups.
-- Input: group names array, mark to set,
--        boolean indicating whether the function is called by a multi group function
--        boolean indicating whether the event has to be recorded into the emaj_hist table
--        name of the rollback target mark when this mark is created by the logged_rollback functions (NULL by default)
--        time stamp identifier to reuse (NULL by default) (this parameter is set when the mark is a rollback start mark)
-- Output: number of processed tables and sequences
-- The insertion of the corresponding event in the emaj_hist table is performed by callers.
  DECLARE
    v_nbTb                   INT = 0;
    v_timestamp              TIMESTAMPTZ;
    r_tblsq                  RECORD;
  BEGIN
-- if requested, record the set mark begin in emaj_hist
    IF v_eventToRecord THEN
      INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
        VALUES (CASE WHEN v_multiGroup THEN 'SET_MARK_GROUPS' ELSE 'SET_MARK_GROUP' END, 'BEGIN', array_to_string(v_groupNames,','), v_mark);
    END IF;
-- get the time stamp of the operation, if not supplied as input parameter
    IF v_timeId IS NULL THEN
      SELECT emaj._set_time_stamp('M') INTO v_timeId;
    END IF;
-- look at the clock to get the 'official' timestamp representing the mark
    SELECT time_clock_timestamp INTO v_timestamp FROM emaj.emaj_time_stamp WHERE time_id = v_timeId;
-- process sequences as early as possible (no lock protect them from other transactions activity)
    FOR r_tblsq IN
        SELECT rel_priority, rel_schema, rel_tblseq, rel_log_schema FROM emaj.emaj_relation
          WHERE rel_group = ANY (v_groupNames) AND rel_kind = 'S'
          ORDER BY rel_priority, rel_schema, rel_tblseq
      LOOP
-- for each sequence of the groups, record the sequence parameters into the emaj_sequence table
      EXECUTE 'INSERT INTO emaj.emaj_sequence (' ||
               'sequ_schema, sequ_name, sequ_time_id, sequ_last_val, sequ_start_val, ' ||
               'sequ_increment, sequ_max_val, sequ_min_val, sequ_cache_val, sequ_is_cycled, sequ_is_called ' ||
               ') SELECT ' || quote_literal(r_tblsq.rel_schema) || ', ' ||
               quote_literal(r_tblsq.rel_tblseq) || ', ' || v_timeId ||
               ', last_value, start_value, increment_by, max_value, min_value, cache_value, is_cycled, is_called ' ||
               'FROM ' || quote_ident(r_tblsq.rel_schema) || '.' || quote_ident(r_tblsq.rel_tblseq);
      v_nbTb = v_nbTb + 1;
    END LOOP;
-- record the number of log rows for the old last mark of each group
--   the statement returns no row in case of emaj_start_group(s)
    UPDATE emaj.emaj_mark m SET mark_log_rows_before_next =
      coalesce( (SELECT sum(stat_rows) FROM emaj.emaj_log_stat_group(m.mark_group,'EMAJ_LAST_MARK',NULL)) ,0)
      WHERE mark_group = ANY (v_groupNames)
        AND (mark_group, mark_id) IN                   -- select only the last non deleted mark of each concerned group
            (SELECT mark_group, MAX(mark_id) FROM emaj.emaj_mark
             WHERE mark_group = ANY (v_groupNames) AND NOT mark_is_deleted GROUP BY mark_group);
-- for each table of the groups, ...
    FOR r_tblsq IN
        SELECT rel_priority, rel_schema, rel_tblseq, rel_log_schema, rel_log_sequence FROM emaj.emaj_relation
          WHERE rel_group = ANY (v_groupNames) AND rel_kind = 'r'
          ORDER BY rel_priority, rel_schema, rel_tblseq
        LOOP
-- ... record the associated sequence parameters in the emaj sequence table
      EXECUTE 'INSERT INTO emaj.emaj_sequence (' ||
               'sequ_schema, sequ_name, sequ_time_id, sequ_last_val, sequ_start_val, ' ||
               'sequ_increment, sequ_max_val, sequ_min_val, sequ_cache_val, sequ_is_cycled, sequ_is_called ' ||
               ') SELECT '|| quote_literal(r_tblsq.rel_log_schema) || ', ' || quote_literal(r_tblsq.rel_log_sequence) || ', ' ||
               v_timeId || ', last_value, start_value, ' ||
               'increment_by, max_value, min_value, cache_value, is_cycled, is_called ' ||
               'FROM ' || quote_ident(r_tblsq.rel_log_schema) || '.' || quote_ident(r_tblsq.rel_log_sequence);
      v_nbTb = v_nbTb + 1;
    END LOOP;
-- record the marks into the emaj_mark table
    FOR v_i IN 1 .. array_upper(v_groupNames,1) LOOP
      INSERT INTO emaj.emaj_mark (mark_group, mark_name, mark_time_id, mark_is_deleted, mark_is_rlbk_protected, mark_logged_rlbk_target_mark)
        SELECT v_groupNames[v_i], v_mark, v_timeId, FALSE, FALSE, v_loggedRlbkTargetMark
          FROM emaj.emaj_time_stamp WHERE time_id = v_timeId;
    END LOOP;
-- before exiting, cleanup the state of the pending rollback events from the emaj_rlbk table
    IF emaj._dblink_is_cnx_opened('rlbk#1') THEN
-- ... either through dblink if we are currently performing a rollback with a dblink connection already opened
--     this is mandatory to avoid deadlock
      PERFORM 0 FROM dblink('rlbk#1','SELECT emaj.emaj_cleanup_rollback_state()') AS (dummy INT);
    ELSE
-- ... or directly
      PERFORM emaj.emaj_cleanup_rollback_state();
    END IF;
-- if requested, record the set mark end in emaj_hist
    IF v_eventToRecord THEN
      INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
        VALUES (CASE WHEN v_multiGroup THEN 'SET_MARK_GROUPS' ELSE 'SET_MARK_GROUP' END, 'END', array_to_string(v_groupNames,','), v_mark);
    END IF;
--
    RETURN v_nbTb;
  END;
$_set_mark_groups$;

CREATE OR REPLACE FUNCTION emaj.emaj_comment_mark_group(v_groupName TEXT, v_mark TEXT, v_comment TEXT)
RETURNS VOID LANGUAGE plpgsql AS
$emaj_comment_mark_group$
-- This function sets or modifies a comment on a mark by updating the mark_comment of the emaj_mark table.
-- Input: group name, mark to comment, comment
--   The keyword 'EMAJ_LAST_MARK' can be used as mark to delete to specify the last set mark.
--   To reset an existing comment for a mark, the supplied comment can be NULL.
  DECLARE
    v_realMark               TEXT;
  BEGIN
-- check that the group is recorded in emaj_group table
    PERFORM 0 FROM emaj.emaj_group WHERE group_name = v_groupName FOR UPDATE;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_comment_mark_group: group "%" has not been created.', v_groupName;
    END IF;
-- retrieve and check the mark name
    SELECT emaj._get_mark_name(v_groupName,v_mark) INTO v_realMark;
    IF v_realMark IS NULL THEN
      RAISE EXCEPTION 'emaj_comment_mark_group: "%" is not a known mark for group "%".', v_mark, v_groupName;
    END IF;
-- OK, update the mark_comment from emaj_mark table
    UPDATE emaj.emaj_mark SET mark_comment = v_comment WHERE mark_group = v_groupName AND mark_name = v_realMark;
-- insert event in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_object, hist_wording)
      VALUES ('COMMENT_MARK_GROUP', v_groupName, 'Mark ' || v_realMark);
    RETURN;
  END;
$emaj_comment_mark_group$;
COMMENT ON FUNCTION emaj.emaj_comment_mark_group(TEXT,TEXT,TEXT) IS
$$Sets a comment on a mark for an E-Maj group.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_get_previous_mark_group(v_groupName TEXT, v_datetime TIMESTAMPTZ)
RETURNS TEXT LANGUAGE plpgsql AS
$emaj_get_previous_mark_group$
-- This function returns the name of the mark that immediately precedes a given date and time.
-- It may return unpredictable result in case of system date or time change.
-- The function can be called by both emaj_adm and emaj_viewer roles.
-- Input: group name, date and time
-- Output: mark name, or NULL if there is no mark before the given date and time
  DECLARE
    v_markName               TEXT;
  BEGIN
-- check that the group is recorded in emaj_group table
    PERFORM 0 FROM emaj.emaj_group WHERE group_name = v_groupName;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_get_previous_mark_group (1): group "%" has not been created.', v_groupName;
    END IF;
-- find the requested mark
    SELECT mark_name INTO v_markName FROM emaj.emaj_mark, emaj.emaj_time_stamp
      WHERE mark_time_id = time_id AND mark_group = v_groupName AND time_clock_timestamp < v_datetime
      ORDER BY time_clock_timestamp DESC LIMIT 1;
    IF NOT FOUND THEN
      RETURN NULL;
    ELSE
      RETURN v_markName;
    END IF;
  END;
$emaj_get_previous_mark_group$;
COMMENT ON FUNCTION emaj.emaj_get_previous_mark_group(TEXT,TIMESTAMPTZ) IS
$$Returns the latest mark name preceeding a point in time.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_get_previous_mark_group(v_groupName TEXT, v_mark TEXT)
RETURNS TEXT LANGUAGE plpgsql AS
$emaj_get_previous_mark_group$
-- This function returns the name of the mark that immediately precedes a given mark for a group.
-- The function can be called by both emaj_adm and emaj_viewer roles.
-- Input: group name, mark name
--   The keyword 'EMAJ_LAST_MARK' can be used to specify the last set mark.
-- Output: mark name, or NULL if there is no mark before the given mark
  DECLARE
    v_realMark               TEXT;
    v_markName               TEXT;
  BEGIN
-- check that the group is recorded in emaj_group table
    PERFORM 0 FROM emaj.emaj_group WHERE group_name = v_groupName;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_get_previous_mark_group (2): group "%" has not been created.', v_groupName;
    END IF;
-- retrieve and check the given mark name
    SELECT emaj._get_mark_name(v_groupName,v_mark) INTO v_realMark;
    IF v_realMark IS NULL THEN
      RAISE EXCEPTION 'emaj_get_previous_mark_group: "%" is not a known mark for group "%".', v_mark, v_groupName;
    END IF;
-- find the requested mark
    SELECT mark_name INTO v_markName FROM emaj.emaj_mark
      WHERE mark_group = v_groupName AND mark_time_id <
        (SELECT mark_time_id FROM emaj.emaj_mark WHERE mark_group = v_groupName AND mark_name = v_realMark)
      ORDER BY mark_time_id DESC LIMIT 1;
    IF NOT FOUND THEN
      RETURN NULL;
    ELSE
      RETURN v_markName;
    END IF;
  END;
$emaj_get_previous_mark_group$;
COMMENT ON FUNCTION emaj.emaj_get_previous_mark_group(TEXT,TEXT) IS
$$Returns the latest mark name preceeding a given mark for a group.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_delete_mark_group(v_groupName TEXT, v_mark TEXT)
RETURNS INT LANGUAGE plpgsql AS
$emaj_delete_mark_group$
-- This function deletes all traces from a previous set_mark_group(s) function.
-- Then, any rollback on the deleted mark will not be possible.
-- It deletes rows corresponding to the mark to delete from emaj_mark and emaj_sequence
-- If this mark is the first mark, it also deletes rows from all concerned log tables and holes from emaj_seq_hole.
-- The statistical mark_log_rows_before_next column's content of the previous mark is also maintained
-- At least one mark must remain after the operation (otherwise it is not worth having a group in LOGGING state !).
-- Input: group name, mark to delete
--   The keyword 'EMAJ_LAST_MARK' can be used as mark to delete to specify the last set mark.
-- Output: number of deleted marks, i.e. 1
  DECLARE
    v_realMark               TEXT;
    v_markId                 BIGINT;
    v_MarkTimeId             BIGINT;
    v_idNewMin               BIGINT;
    v_markNewMin             TEXT;
    v_cpt                    INT;
  BEGIN
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('DELETE_MARK_GROUP', 'BEGIN', v_groupName, v_mark);
-- check that the group is recorded in emaj_group table
    PERFORM 1 FROM emaj.emaj_group WHERE group_name = v_groupName FOR UPDATE;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_delete_mark_group: group "%" has not been created.', v_groupName;
    END IF;
-- retrieve and check the mark name
    SELECT emaj._get_mark_name(v_groupName,v_mark) INTO v_realMark;
    IF v_realMark IS NULL THEN
      RAISE EXCEPTION 'emaj_delete_mark_group: "%" is not a known mark for group "%".', v_mark, v_groupName;
    END IF;
-- count the number of marks in the group
    SELECT count(*) INTO v_cpt FROM emaj.emaj_mark WHERE mark_group = v_groupName;
-- and check there are at least 2 marks for the group
    IF v_cpt < 2 THEN
      RAISE EXCEPTION 'emaj_delete_mark_group: "%" is the only mark of the group. It cannot be deleted.', v_mark;
    END IF;
-- OK, now get the id and time stamp id of the mark to delete
    SELECT mark_id, mark_time_id INTO v_markId, v_MarkTimeId
      FROM emaj.emaj_mark WHERE mark_group = v_groupName AND mark_name = v_realMark;
-- ... and the id and timestamp of the future first mark
    SELECT mark_id, mark_name INTO v_idNewMin, v_markNewMin
      FROM emaj.emaj_mark WHERE mark_group = v_groupName AND mark_name <> v_realMark ORDER BY mark_id LIMIT 1;
    IF v_markId < v_idNewMin THEN
-- if the mark to delete is the first one, process its deletion with _delete_between_marks_group(), as the first rows of log tables become useless
      PERFORM emaj._delete_between_marks_group(v_groupName, NULL, v_markNewMin);
    ELSE
-- otherwise, process its deletion with _delete_intermediate_mark_group()
      PERFORM emaj._delete_intermediate_mark_group(v_groupName, v_realMark, v_markId, v_MarkTimeId);
    END IF;
-- insert end in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('DELETE_MARK_GROUP', 'END', v_groupName, v_realMark);
    RETURN 1;
  END;
$emaj_delete_mark_group$;
COMMENT ON FUNCTION emaj.emaj_delete_mark_group(TEXT,TEXT) IS
$$Deletes a mark for an E-Maj group.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_delete_before_mark_group(v_groupName TEXT, v_mark TEXT)
RETURNS INT LANGUAGE plpgsql AS
$emaj_delete_before_mark_group$
-- This function deletes all marks set before a given mark.
-- Then, any rollback on the deleted marks will not be possible.
-- It deletes rows corresponding to the marks to delete from emaj_mark, emaj_sequence, emaj_seq_hole.
-- It also deletes rows from all concerned log tables.
-- Input: group name, name of the new first mark
--   The keyword 'EMAJ_LAST_MARK' can be used as mark name.
-- Output: number of deleted marks
--   or NULL if the provided mark name is NULL
  DECLARE
    v_realMark               TEXT;
    v_nbMark                 INT;
  BEGIN
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('DELETE_BEFORE_MARK_GROUP', 'BEGIN', v_groupName, v_mark);
-- check that the group is recorded in emaj_group table
    PERFORM 1 FROM emaj.emaj_group WHERE group_name = v_groupName FOR UPDATE;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_delete_before_mark_group: group "%" has not been created.', v_groupName;
    END IF;
-- return NULL if mark name is NULL
    IF v_mark IS NULL THEN
      RETURN NULL;
    END IF;
-- retrieve and check the mark name
    SELECT emaj._get_mark_name(v_groupName,v_mark) INTO v_realMark;
    IF v_realMark IS NULL THEN
      RAISE EXCEPTION 'emaj_delete_before_mark_group: "%" is not a known mark for group "%".', v_mark, v_groupName;
    END IF;
-- effectively delete all marks before the supplied mark
    SELECT (emaj._delete_between_marks_group(v_groupName, NULL, v_realMark)).v_nbMark INTO v_nbMark;
-- insert end in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('DELETE_BEFORE_MARK_GROUP', 'END', v_groupName,  v_nbMark || ' marks deleted ; ' || v_realMark || ' is now the initial mark' );
    RETURN v_nbMark;
  END;
$emaj_delete_before_mark_group$;
COMMENT ON FUNCTION emaj.emaj_delete_before_mark_group(TEXT,TEXT) IS
$$Deletes all marks preceeding a given mark for an E-Maj group.$$;

CREATE OR REPLACE FUNCTION emaj._delete_between_marks_group(v_groupName TEXT, v_firstMark TEXT, v_lastMark TEXT, OUT v_nbMark INT, OUT v_nbTbl INT)
RETURNS RECORD LANGUAGE plpgsql AS
$_delete_between_marks_group$
-- This function deletes all logs and intermediate marks set between two given marks.
-- The function is called by the emaj_delete_before_mark_group(), emaj_delete_mark_group() and emaj_consolidate_rollback_group() functions.
-- It deletes rows corresponding to the marks to delete from emaj_mark and emaj_sequence.
-- It deletes rows from all concerned log tables.
-- It also manages sequence holes in emaj_seq_hole.
-- To complete, the function deletes oldest rows from emaj_hist.
-- Input: group name, name of both marks that defines the range to delete.
--        when the first mark is NULL, it represents the very first known mark.
-- Output: number of deleted marks, number of tables effectively processed (for which at least one log row has been deleted)
  DECLARE
    v_firstMarkId            BIGINT;
    v_firstMarkGlobalSeq     BIGINT;
    v_firstMarkTimeId        BIGINT;
    v_lastMarkId             BIGINT;
    v_lastMarkGlobalSeq      BIGINT;
    v_lastMarkTimeId        BIGINT;
    v_nbUpd                  BIGINT;
    r_rel                    RECORD;
  BEGIN
-- retrieve the id, the timestamp and the emaj_gid value and the time stamp id of the first mark, if supplied
    IF v_firstMark IS NOT NULL THEN
      SELECT mark_id, time_last_emaj_gid, mark_time_id INTO v_firstMarkId, v_firstMarkGlobalSeq, v_firstMarkTimeId
        FROM emaj.emaj_mark, emaj.emaj_time_stamp
        WHERE mark_time_id = time_id AND mark_group = v_groupName AND mark_name = v_firstMark;
      ELSE
        v_firstMarkId = 0; v_firstMarkTimeId = 0; v_firstMarkGlobalSeq = 0;
    END IF;
-- retrieve the id, the timestamp and the emaj_gid value and the time stamp id of the last mark
    SELECT mark_id, time_last_emaj_gid, mark_time_id INTO v_lastMarkId, v_lastMarkGlobalSeq, v_lastMarkTimeId
      FROM emaj.emaj_mark, emaj.emaj_time_stamp
      WHERE mark_time_id = time_id AND mark_group = v_groupName AND mark_name = v_lastMark;
-- delete rows from all log tables (no need to try to delete if v_firstMarkGlobalSeq and v_lastMarkGlobalSeq are equal)
    v_nbTbl = 0;
    IF v_firstMarkGlobalSeq < v_lastMarkGlobalSeq THEN
-- loop on all tables of the group
      FOR r_rel IN
          SELECT quote_ident(rel_log_schema) || '.' || quote_ident(rel_log_table) AS log_table_name FROM emaj.emaj_relation
            WHERE rel_group = v_groupName AND rel_kind = 'r'
            ORDER BY rel_priority, rel_schema, rel_tblseq
      LOOP
-- delete log rows prior to the new first mark
        EXECUTE 'DELETE FROM ' || r_rel.log_table_name || ' WHERE emaj_gid > ' || v_firstMarkGlobalSeq || ' AND emaj_gid <= ' || v_lastMarkGlobalSeq;
        GET DIAGNOSTICS v_nbUpd = ROW_COUNT;
        IF v_nbUpd > 0 THEN
           v_nbTbl = v_nbTbl + 1;
        END IF;
      END LOOP;
    END IF;
-- process emaj_seq_hole content
-- delete all existing holes (if any) between both marks
    DELETE FROM emaj.emaj_seq_hole USING emaj.emaj_relation
      WHERE rel_group = v_groupName AND rel_kind = 'r' AND rel_schema = sqhl_schema AND rel_tblseq = sqhl_table
        AND sqhl_begin_time_id >= v_firstMarkTimeId AND sqhl_begin_time_id < v_lastMarkTimeId;
    IF v_firstMark IS NOT NULL THEN
-- and if not deleting the oldest marks, create holes representing the deleted logs
--   one hole for each application table for which logs have been deleted by this operation or by a previous rollback
--   the hole sizes are computed using the sequence last values recorded into the emaj_sequence table
      INSERT INTO emaj.emaj_seq_hole (sqhl_schema, sqhl_table, sqhl_begin_time_id, sqhl_end_time_id, sqhl_hole_size)
        SELECT rel_schema, rel_tblseq, v_firstMarkTimeId, v_lastMarkTimeId,
               (SELECT CASE WHEN sequ_is_called THEN sequ_last_val + sequ_increment ELSE sequ_last_val END FROM emaj.emaj_sequence
                  WHERE sequ_schema = rel_log_schema AND sequ_name = rel_log_sequence AND sequ_time_id = v_lastMarkTimeId)
               -
               (SELECT CASE WHEN sequ_is_called THEN sequ_last_val + sequ_increment ELSE sequ_last_val END FROM emaj.emaj_sequence
                  WHERE sequ_schema = rel_log_schema AND sequ_name = rel_log_sequence AND sequ_time_id = v_firstMarkTimeId)
          FROM emaj.emaj_relation
          WHERE rel_group = v_groupName AND rel_kind = 'r'
            AND 0 <
               (SELECT CASE WHEN sequ_is_called THEN sequ_last_val + sequ_increment ELSE sequ_last_val END FROM emaj.emaj_sequence
                  WHERE sequ_schema = rel_log_schema AND sequ_name = rel_log_sequence AND sequ_time_id = v_lastMarkTimeId)
               -
               (SELECT CASE WHEN sequ_is_called THEN sequ_last_val + sequ_increment ELSE sequ_last_val END FROM emaj.emaj_sequence
                  WHERE sequ_schema = rel_log_schema AND sequ_name = rel_log_sequence AND sequ_time_id = v_firstMarkTimeId);
    END IF;
-- now the sequences related to the mark to delete can be suppressed
--   delete first application sequences related data for the group
    DELETE FROM emaj.emaj_sequence USING emaj.emaj_relation
      WHERE rel_group = v_groupName AND rel_kind = 'S'
        AND sequ_schema = rel_schema AND sequ_name = rel_tblseq
        AND sequ_time_id > v_firstMarkTimeId AND sequ_time_id < v_lastMarkTimeId;
--   delete then emaj sequences related data for the group
    DELETE FROM emaj.emaj_sequence USING emaj.emaj_relation
      WHERE rel_group = v_groupName AND rel_kind = 'r'
        AND sequ_schema = rel_log_schema AND sequ_name = rel_log_sequence
        AND sequ_time_id > v_firstMarkTimeId AND sequ_time_id < v_lastMarkTimeId;
-- in emaj_mark, reset the mark_logged_rlbk_target_mark column to null for marks of the group that will remain
--    and that may have one of the deleted marks as target mark from a previous logged rollback operation
    UPDATE emaj.emaj_mark SET mark_logged_rlbk_target_mark = NULL
      WHERE mark_group = v_groupName AND mark_id >= v_lastMarkId
        AND mark_logged_rlbk_target_mark IN (
            SELECT mark_name FROM emaj.emaj_mark
              WHERE mark_group = v_groupName AND mark_id > v_firstMarkId AND mark_id < v_lastMarkId
            );
-- if not deleting the oldest marks, set the mark_log_rows_before_next of the first mark to 0
    IF v_firstMark IS NOT NULL THEN
      UPDATE emaj.emaj_mark SET mark_log_rows_before_next = 0
        WHERE mark_group = v_groupName AND mark_name = v_firstMark;
    END IF;
-- and finaly delete all intermediate marks
    DELETE FROM emaj.emaj_mark WHERE mark_group = v_groupName AND mark_id > v_firstMarkId AND mark_id < v_lastMarkId;
    GET DIAGNOSTICS v_nbMark = ROW_COUNT;
-- purge the emaj history, if needed (even if no mark as been really dropped)
    PERFORM emaj._purge_hist();
    RETURN;
  END;
$_delete_between_marks_group$;

CREATE OR REPLACE FUNCTION emaj._delete_intermediate_mark_group(v_groupName TEXT, v_markName TEXT, v_markId BIGINT, v_markTimeId BIGINT)
RETURNS VOID LANGUAGE plpgsql AS
$_delete_intermediate_mark_group$
-- This function effectively deletes an intermediate mark for a group.
-- It is called by the emaj_delete_mark_group() function.
-- It deletes rows corresponding to the mark to delete from emaj_mark and emaj_sequence
-- The statistical mark_log_rows_before_next column's content of the previous mark is also maintained
-- Input: group name, mark name, mark id and mark time stamp id of the mark to delete
  DECLARE
    v_previousMark           TEXT;
    v_nextMark               TEXT;
  BEGIN
-- delete the sequences related to the mark to delete
--   delete first application sequences related data for the group
    DELETE FROM emaj.emaj_sequence USING emaj.emaj_relation
      WHERE sequ_time_id = v_markTimeId
        AND rel_group = v_groupName AND rel_kind = 'S'
        AND sequ_schema = rel_schema AND sequ_name = rel_tblseq;
--   delete then emaj sequences related data for the group
    DELETE FROM emaj.emaj_sequence USING emaj.emaj_relation
      WHERE sequ_time_id = v_markTimeId
        AND rel_group = v_groupName AND rel_kind = 'r'
        AND sequ_schema = rel_log_schema AND sequ_name = rel_log_sequence;
-- physically delete the mark from emaj_mark
    DELETE FROM emaj.emaj_mark WHERE mark_group = v_groupName AND mark_name = v_markName;
-- adjust the mark_log_rows_before_next column of the previous mark
-- get the name of the mark immediately preceeding the mark to delete
    SELECT mark_name INTO v_previousMark FROM emaj.emaj_mark
      WHERE mark_group = v_groupName AND mark_id < v_markId ORDER BY mark_id DESC LIMIT 1;
-- get the name of the first mark succeeding the mark to delete
    SELECT mark_name INTO v_nextMark FROM emaj.emaj_mark
      WHERE mark_group = v_groupName AND mark_id > v_markId ORDER BY mark_id LIMIT 1;
    IF NOT FOUND THEN
-- no next mark, so update the previous mark with NULL
      UPDATE emaj.emaj_mark SET mark_log_rows_before_next = NULL
        WHERE mark_group = v_groupName AND mark_name = v_previousMark;
    ELSE
-- update the previous mark with the emaj_log_stat_group() call's result
      UPDATE emaj.emaj_mark SET mark_log_rows_before_next =
          (SELECT sum(stat_rows) FROM emaj.emaj_log_stat_group(v_groupName, v_previousMark, v_nextMark))
        WHERE mark_group = v_groupName AND mark_name = v_previousMark;
    END IF;
-- reset the mark_logged_rlbk_target_mark column to null for other marks of the group
--   that may have the deleted mark as target mark from a previous logged rollback operation
    UPDATE emaj.emaj_mark SET mark_logged_rlbk_target_mark = NULL
      WHERE mark_group = v_groupName AND mark_logged_rlbk_target_mark = v_markName;
    RETURN;
  END;
$_delete_intermediate_mark_group$;

CREATE OR REPLACE FUNCTION emaj.emaj_rename_mark_group(v_groupName TEXT, v_mark TEXT, v_newName TEXT)
RETURNS VOID LANGUAGE plpgsql AS
$emaj_rename_mark_group$
-- This function renames an existing mark.
-- The group can be in LOGGING or not.
-- Rows from emaj_mark and emaj_sequence tables are updated accordingly.
-- Input: group name, mark to rename, new name for the mark
--   The keyword 'EMAJ_LAST_MARK' can be used as mark to rename to specify the last set mark.
  DECLARE
    v_realMark               TEXT;
  BEGIN
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('RENAME_MARK_GROUP', 'BEGIN', v_groupName, v_mark);
-- check that the group is recorded in emaj_group table
    PERFORM 0 FROM emaj.emaj_group WHERE group_name = v_groupName FOR UPDATE;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_rename_mark_group: group "%" has not been created.', v_groupName;
    END IF;
-- retrieve and check the mark name
    SELECT emaj._get_mark_name(v_groupName,v_mark) INTO v_realMark;
    IF v_realMark IS NULL THEN
      RAISE EXCEPTION 'emaj_rename_mark_group: mark "%" does not exist for group "%".', v_mark, v_groupName;
    END IF;
-- check the new mark name is not 'EMAJ_LAST_MARK' or NULL
    IF v_newName = 'EMAJ_LAST_MARK' OR v_newName IS NULL THEN
       RAISE EXCEPTION 'emaj_rename_mark_group: "%" is not an allowed name for a new mark.', v_newName;
    END IF;
-- check if the new mark name doesn't exist for the group
    PERFORM 0 FROM emaj.emaj_mark
      WHERE mark_group = v_groupName AND mark_name = v_newName;
    IF FOUND THEN
       RAISE EXCEPTION 'emaj_rename_mark_group: a mark "%" already exists for group "%".', v_newName, v_groupName;
    END IF;
-- OK, update the emaj_mark table
    UPDATE emaj.emaj_mark SET mark_name = v_newName
      WHERE mark_group = v_groupName AND mark_name = v_realMark;
-- also rename mark names recorded in the mark_logged_rlbk_target_mark column if needed
    UPDATE emaj.emaj_mark SET mark_logged_rlbk_target_mark = v_newName
      WHERE mark_group = v_groupName AND mark_logged_rlbk_target_mark = v_realMark;
-- insert end in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('RENAME_MARK_GROUP', 'END', v_groupName, v_realMark || ' renamed ' || v_newName);
    RETURN;
  END;
$emaj_rename_mark_group$;
COMMENT ON FUNCTION emaj.emaj_rename_mark_group(TEXT,TEXT,TEXT) IS
$$Renames a mark for an E-Maj group.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_protect_mark_group(v_groupName TEXT, v_mark TEXT)
RETURNS INT LANGUAGE plpgsql AS
$emaj_protect_mark_group$
-- This function sets a protection on a mark for a group against accidental rollback.
-- Input: group name, mark to protect
-- Output: 1 if successful, 0 if the mark was already in protected state
-- The group must be ROLLBACKABLE and in LOGGING state.
  DECLARE
    v_groupIsRollbackable    BOOLEAN;
    v_groupIsLogging         BOOLEAN;
    v_realMark               TEXT;
    v_markIsProtected        BOOLEAN;
    v_status                 INT;
  BEGIN
-- check that the group is recorded in emaj_group table
    SELECT group_is_rollbackable, group_is_logging INTO v_groupIsRollbackable, v_groupIsLogging
      FROM emaj.emaj_group WHERE group_name = v_groupName FOR UPDATE;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_protect_mark_group: group "%" has not been created.', v_groupName;
    END IF;
-- check that the group is ROLLBACKABLE
    IF NOT v_groupIsRollbackable THEN
      RAISE EXCEPTION 'emaj_protect_mark_group: A mark on the group "%" cannot be protected because it is an AUDIT_ONLY group.', v_groupName;
    END IF;
-- check that the group is not in LOGGING state
    IF NOT v_groupIsLogging THEN
      RAISE EXCEPTION 'emaj_protect_mark_group: A mark on the group "%" cannot be protected because it is not in LOGGING state.', v_groupName;
    END IF;
-- retrieve and check the mark name
    SELECT emaj._get_mark_name(v_groupName,v_mark) INTO v_realMark;
    IF v_realMark IS NULL THEN
      RAISE EXCEPTION 'emaj_protect_mark_group: mark "%" does not exist for group "%".', v_mark, v_groupName;
    END IF;
-- OK, set the protection
    SELECT mark_is_rlbk_protected INTO v_markIsProtected FROM emaj.emaj_mark
      WHERE mark_group = v_groupName AND mark_name = v_realMark;
    IF v_markIsProtected THEN
      v_status = 0;
    ELSE
      UPDATE emaj.emaj_mark SET mark_is_rlbk_protected = TRUE WHERE mark_group = v_groupName AND mark_name = v_realMark;
      v_status = 1;
    END IF;
-- insert event in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_object, hist_wording)
      VALUES ('PROTECT_MARK_GROUP', v_groupName, 'Mark ' || v_realMark || ' ; status ' || v_status);
    RETURN v_status;
  END;
$emaj_protect_mark_group$;
COMMENT ON FUNCTION emaj.emaj_protect_mark_group(TEXT,TEXT) IS
$$Sets a protection against a rollback on a mark of an E-Maj group.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_unprotect_mark_group(v_groupName TEXT, v_mark TEXT)
RETURNS INT LANGUAGE plpgsql AS
$emaj_unprotect_mark_group$
-- This function unsets a protection on a mark for a group against accidental rollback.
-- Input: group name, mark to unprotect
-- Output: 1 if successful, 0 if the mark was already in unprotected state
-- The group must be ROLLBACKABLE and in LOGGING state.
  DECLARE
    v_groupIsRollbackable    BOOLEAN;
    v_realMark               TEXT;
    v_markIsProtected        BOOLEAN;
    v_status                 INT;
  BEGIN
-- check that the group is recorded in emaj_group table
    SELECT group_is_rollbackable INTO v_groupIsRollbackable
      FROM emaj.emaj_group WHERE group_name = v_groupName FOR UPDATE;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_unprotect_mark_group: group "%" has not been created.', v_groupName;
    END IF;
-- check that the group is ROLLBACKABLE
    IF NOT v_groupIsRollbackable THEN
      RAISE EXCEPTION 'emaj_unprotect_mark_group: A mark on the group "%" cannot be unprotected because it is an AUDIT_ONLY group.', v_groupName;
    END IF;
-- retrieve and check the mark name
    SELECT emaj._get_mark_name(v_groupName,v_mark) INTO v_realMark;
    IF v_realMark IS NULL THEN
      RAISE EXCEPTION 'emaj_unprotect_mark_group: mark "%" does not exist for group "%".', v_mark, v_groupName;
    END IF;
-- OK, set the protection
    SELECT mark_is_rlbk_protected INTO v_markIsProtected FROM emaj.emaj_mark
      WHERE mark_group = v_groupName AND mark_name = v_realMark;
    IF NOT v_markIsProtected THEN
      v_status = 0;
    ELSE
      UPDATE emaj.emaj_mark SET mark_is_rlbk_protected = FALSE WHERE mark_group = v_groupName AND mark_name = v_realMark;
      v_status = 1;
    END IF;
-- insert event in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_object, hist_wording)
      VALUES ('UNPROTECT_MARK_GROUP', v_groupName, 'Mark ' || v_realMark || ' ; status ' || v_status);
    RETURN v_status;
  END;
$emaj_unprotect_mark_group$;
COMMENT ON FUNCTION emaj.emaj_unprotect_mark_group(TEXT,TEXT) IS
$$Unsets a protection against a rollback on a mark of an E-Maj group.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_rollback_group(v_groupName TEXT, v_mark TEXT)
RETURNS INT LANGUAGE plpgsql AS
$emaj_rollback_group$
-- The function rollbacks all tables and sequences of a group up to a mark in the history
-- Input: group name, mark in the history, as it is inserted by emaj.emaj_set_mark_group(s)
-- Output: number of processed tables and sequences
  BEGIN
-- just (unlogged) rollback the group (with boolean: isLoggedRlbk = false, multiGroup = false)
    RETURN emaj._rlbk_groups(array[v_groupName], v_mark, false, false);
  END;
$emaj_rollback_group$;
COMMENT ON FUNCTION emaj.emaj_rollback_group(TEXT,TEXT) IS
$$Rollbacks an E-Maj group to a given mark.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_rollback_groups(v_groupNames TEXT[], v_mark TEXT)
RETURNS INT LANGUAGE plpgsql AS
$emaj_rollback_groups$
-- The function rollbacks all tables and sequences of a group array up to a mark in the history
-- Input: array of group names, mark in the history, as it is inserted by emaj.emaj_set_mark_group(s)
-- Output: number of processed tables and sequences
  BEGIN
-- just (unlogged) rollback the groups (with boolean: isLoggedRlbk = false, multiGroup = true)
    RETURN emaj._rlbk_groups(emaj._check_names_array(v_groupNames,'group'), v_mark, false, true);
  END;
$emaj_rollback_groups$;
COMMENT ON FUNCTION emaj.emaj_rollback_groups(TEXT[],TEXT) IS
$$Rollbacks an set of E-Maj groups to a given mark.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_logged_rollback_group(v_groupName TEXT, v_mark TEXT)
RETURNS INT LANGUAGE plpgsql AS
$emaj_logged_rollback_group$
-- The function performs a logged rollback of all tables and sequences of a group up to a mark in the history.
-- A logged rollback is a rollback which can be later rolled back! To achieve this:
-- - log triggers are not disabled at rollback time,
-- - a mark is automaticaly set at the beginning and at the end of the rollback operation,
-- - rolled back log rows and any marks inside the rollback time frame are kept.
-- Input: group name, mark in the history, as it is inserted by emaj.emaj_set_mark_group(s)
-- Output: number of processed tables and sequences
  BEGIN
-- just "logged-rollback" the group (with boolean: isLoggedRlbk = true, multiGroup = false)
    RETURN emaj._rlbk_groups(array[v_groupName], v_mark, true, false);
  END;
$emaj_logged_rollback_group$;
COMMENT ON FUNCTION emaj.emaj_logged_rollback_group(TEXT,TEXT) IS
$$Performs a logged (cancellable) rollbacks of an E-Maj group to a given mark.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_logged_rollback_groups(v_groupNames TEXT[], v_mark TEXT)
RETURNS INT LANGUAGE plpgsql AS
$emaj_logged_rollback_groups$
-- The function performs a logged rollback of all tables and sequences of a groups array up to a mark in the history.
-- A logged rollback is a rollback which can be later rolled back! To achieve this:
-- - log triggers are not disabled at rollback time,
-- - a mark is automaticaly set at the beginning and at the end of the rollback operation,
-- - rolled back log rows and any marks inside the rollback time frame are kept.
-- Input: array of group names, mark in the history, as it is inserted by emaj.emaj_set_mark_group(s)
-- Output: number of tables and sequences effectively processed
  BEGIN
-- just "logged-rollback" the groups (with boolean: isLoggedRlbk = true, multiGroup = true)
    RETURN emaj._rlbk_groups(emaj._check_names_array(v_groupNames,'group'), v_mark, true, true);
  END;
$emaj_logged_rollback_groups$;
COMMENT ON FUNCTION emaj.emaj_logged_rollback_groups(TEXT[],TEXT) IS
$$Performs a logged (cancellable) rollbacks for a set of E-Maj groups to a given mark.$$;

CREATE OR REPLACE FUNCTION emaj._rlbk_init(v_groupNames TEXT[], v_mark TEXT, v_isLoggedRlbk BOOLEAN, v_nbSession INT, v_multiGroup BOOLEAN)
RETURNS INT LANGUAGE plpgsql AS
$_rlbk_init$
-- This is the first step of a rollback group processing.
-- It tests the environment, the supplied parameters and the foreign key constraints.
-- By calling the _rlbk_planning() function, it defines the different elementary steps needed for the operation,
-- and spread the load on the requested number of sessions.
-- It returns a rollback id that will be needed by next steps.
  DECLARE
    v_markName               TEXT;
    v_markTimeId             BIGINT;
    v_markTimestamp          TIMESTAMPTZ;
    v_msg                    TEXT;
    v_nbTblInGroups          INT;
    v_nbSeqInGroups          INT;
    v_dbLinkCnxStatus        INT;
    v_isDblinkUsable         BOOLEAN = false;
    v_effNbTable             INT;
    v_histId                 BIGINT;
    v_stmt                   TEXT;
    v_rlbkId                 INT;
  BEGIN
-- lock the groups to rollback
    PERFORM 1 FROM emaj.emaj_group WHERE group_name = ANY(v_groupNames) FOR UPDATE;
-- check supplied group names and mark parameters
    SELECT emaj._rlbk_check(v_groupNames, v_mark) INTO v_markName;
-- check that no group is damaged
    PERFORM 0 FROM emaj._verify_groups(v_groupNames, true);
-- get the time stamp id and its clock timestamp for the 1st group (as we know this time stamp is the same for all groups of the array)
    SELECT emaj._get_mark_time_id(v_groupNames[1], v_mark) INTO v_markTimeId;
    SELECT time_clock_timestamp INTO v_markTimestamp
      FROM emaj.emaj_time_stamp WHERE time_id = v_markTimeId;
-- insert begin in the history
    IF v_isLoggedRlbk THEN
      v_msg = 'Logged';
    ELSE
      v_msg = 'Unlogged';
    END IF;
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES (CASE WHEN v_multiGroup THEN 'ROLLBACK_GROUPS' ELSE 'ROLLBACK_GROUP' END, 'BEGIN',
              array_to_string(v_groupNames,','),
              v_msg || ' rollback to mark ' || v_markName || ' [' || v_markTimestamp || ']'
             ) RETURNING hist_id INTO v_histId;
-- get the total number of tables for these groups
    SELECT sum(group_nb_table), sum(group_nb_sequence) INTO v_nbTblInGroups, v_nbSeqInGroups
      FROM emaj.emaj_group WHERE group_name = ANY (v_groupNames) ;
-- first try to open a dblink connection
    SELECT emaj._dblink_open_cnx('rlbk#1') INTO v_dbLinkCnxStatus;
    v_isDblinkUsable = (v_dbLinkCnxStatus >= 0);
-- for parallel rollback (nb sessions > 1) the dblink connection must be ok
    IF v_nbSession > 1 AND NOT v_isDblinkUsable THEN
      RAISE EXCEPTION '_rlbk_init: cannot use several sessions without dblink connection capability. (Status of the dblink connection attempt = % - see E-Maj documentation)', v_dbLinkCnxStatus;
    END IF;
-- create the row representing the rollback event in the emaj_rlbk table and get the rollback id back
    v_stmt = 'INSERT INTO emaj.emaj_rlbk (rlbk_groups, rlbk_mark, rlbk_mark_time_id, rlbk_is_logged, ' ||
             'rlbk_nb_session, rlbk_nb_table, rlbk_nb_sequence, rlbk_status, rlbk_begin_hist_id, ' ||
             'rlbk_is_dblink_used) ' ||
             'VALUES (' || quote_literal(v_groupNames) || ',' || quote_literal(v_markName) || ',' ||
             v_markTimeId || ',' || v_isLoggedRlbk || ',' ||
             v_nbSession || ',' || v_nbTblInGroups || ',' || v_nbSeqInGroups || ', ''PLANNING'',' || v_histId || ',' ||
             v_isDblinkUsable || ') RETURNING rlbk_id';
    IF v_isDblinkUsable THEN
-- insert a rollback event into the emaj_rlbk table ... either through dblink if possible
      SELECT rlbk_id INTO v_rlbkId FROM dblink('rlbk#1',v_stmt) AS (rlbk_id INT);
    ELSE
-- ... or directly
      EXECUTE v_stmt INTO v_rlbkId;
    END IF;
-- issue warnings in case of foreign keys with tables outside the groups
    PERFORM emaj._check_fk_groups(v_groupNames);
-- call the rollback planning function to define all the elementary steps to perform,
-- compute their estimated duration and attribute steps to sessions
    v_stmt = 'SELECT emaj._rlbk_planning(' || v_rlbkId || ')';
    IF v_isDblinkUsable THEN
-- ... either through dblink if possible (do not try to open a connection, it has already been attempted)
      SELECT eff_nb_table FROM dblink('rlbk#1',v_stmt) AS (eff_nb_table INT) INTO v_effNbTable;
    ELSE
-- ... or directly
      EXECUTE v_stmt INTO v_effNbTable;
    END IF;
-- update the emaj_rlbk table to set the real number of tables to process and adjust the rollback status
    v_stmt = 'UPDATE emaj.emaj_rlbk SET rlbk_eff_nb_table = ' || v_effNbTable ||
             ', rlbk_status = ''LOCKING'' ' || ' WHERE rlbk_id = ' || v_rlbkId || ' RETURNING 1';
    IF v_isDblinkUsable THEN
-- ... either through dblink if possible
      PERFORM 0 FROM dblink('rlbk#1',v_stmt) AS (dummy INT);
    ELSE
-- ... or directly
      EXECUTE v_stmt;
    END IF;
    RETURN v_rlbkId;
  END;
$_rlbk_init$;

CREATE OR REPLACE FUNCTION emaj._rlbk_check(v_groupNames TEXT[], v_mark TEXT)
RETURNS TEXT LANGUAGE plpgsql AS
$_rlbk_check$
-- This functions performs checks on group names and mark names supplied as parameter for the emaj_rollback_groups()
-- and emaj_estimate_rollback_groups() functions.
-- It returns the real mark name.
  DECLARE
    v_aGroupName             TEXT;
    v_groupIsLogging         BOOLEAN;
    v_groupIsProtected       BOOLEAN;
    v_groupIsRollbackable    BOOLEAN;
    v_markName               TEXT;
    v_markId                 BIGINT;
    v_markIsDeleted          BOOLEAN;
    v_protectedMarkList      TEXT;
    v_cpt                    INT;
  BEGIN
-- check that each group ...
-- ...is recorded in emaj_group table
    FOREACH v_aGroupName IN ARRAY v_groupNames LOOP
      SELECT group_is_logging, group_is_rollbackable, group_is_rlbk_protected INTO v_groupIsLogging, v_groupIsRollbackable, v_groupIsProtected
        FROM emaj.emaj_group WHERE group_name = v_aGroupName;
      IF NOT FOUND THEN
        RAISE EXCEPTION '_rlbk_check: group "%" has not been created.', v_aGroupName;
      END IF;
-- ... is in LOGGING state
      IF NOT v_groupIsLogging THEN
        RAISE EXCEPTION '_rlbk_check: Group "%" is not in LOGGING state.', v_aGroupName;
      END IF;
-- ... is ROLLBACKABLE
      IF NOT v_groupIsRollbackable THEN
        RAISE EXCEPTION '_rlbk_check: Group "%" has been created for audit only purpose.', v_aGroupName;
      END IF;
-- ... is not protected against rollback
      IF v_groupIsProtected THEN
        RAISE EXCEPTION '_rlbk_check: Group "%" is currently protected against rollback.', v_aGroupName;
      END IF;
-- ... owns the requested mark
      SELECT emaj._get_mark_name(v_aGroupName,v_mark) INTO v_markName;
      IF NOT FOUND OR v_markName IS NULL THEN
        RAISE EXCEPTION '_rlbk_check: No mark "%" exists for group "%".', v_mark, v_aGroupName;
      END IF;
-- ... and this mark is ACTIVE
      SELECT mark_id, mark_is_deleted INTO v_markId, v_markIsDeleted FROM emaj.emaj_mark
        WHERE mark_group = v_aGroupName AND mark_name = v_markName;
      IF v_markIsDeleted THEN
        RAISE EXCEPTION '_rlbk_check: mark "%" for group "%" is not usable for rollback.', v_markName, v_aGroupName;
      END IF;
-- ... and the rollback wouldn't delete protected marks
      SELECT string_agg(mark_name,', ') INTO v_protectedMarkList FROM (
        SELECT mark_name FROM emaj.emaj_mark
          WHERE mark_group = v_aGroupName AND mark_id > v_markId AND mark_is_rlbk_protected
          ORDER BY mark_id) AS t;
      IF v_protectedMarkList IS NOT NULL THEN
        RAISE EXCEPTION '_rlbk_check: protected marks (%) for group "%" block the rollback to mark "%".', v_protectedMarkList, v_aGroupName, v_markName;
      END IF;
    END LOOP;
-- get the mark timestamp and check it is the same for all groups of the array
    SELECT count(DISTINCT emaj._get_mark_time_id(group_name,v_mark)) INTO v_cpt FROM emaj.emaj_group
      WHERE group_name = ANY (v_groupNames);
    IF v_cpt > 1 THEN
      RAISE EXCEPTION '_rlbk_check: Mark "%" does not represent the same point in time for all groups.', v_mark;
    END IF;
    RETURN v_markName;
  END;
$_rlbk_check$;

CREATE OR REPLACE FUNCTION emaj._rlbk_planning(v_rlbkId INT)
RETURNS INT LANGUAGE plpgsql SECURITY DEFINER AS
$_rlbk_planning$
-- This function builds the rollback steps for a rollback operation.
-- It stores the result into the emaj_rlbk_plan table.
-- The function returns the effective number of tables to process.
-- It is called in an autonomous dblink transaction, if possible.
-- The function is defined as SECURITY DEFINER so that emaj_viwer role can write into rollback tables without having specific privileges to do it.
  DECLARE
    v_groupNames             TEXT[];
    v_mark                   TEXT;
    v_isLoggedRlbk           BOOLEAN;
    v_markTimeId             BIGINT;
    v_nbSession              INT;
    v_ctrlStepName           emaj._rlbk_step_enum;
    v_effNbTable             INT;
    v_batchNumber            INT;
    v_checks                 INT;
    v_estimDuration          INTERVAL;
    v_estimMethod            INT;
    v_estimDropFkDuration    INTERVAL;
    v_estimDropFkMethod      INT;
    v_estimSetFkDefDuration  INTERVAL;
    v_estimSetFkDefMethod    INT;
    v_avg_row_rlbk           INTERVAL;
    v_avg_row_del_log        INTERVAL;
    v_avg_fkey_check         INTERVAL;
    v_fixed_step_rlbk        INTERVAL;
    v_fixed_dblink_rlbk      INTERVAL;
    v_sessionLoad            INTERVAL[];
    v_minSession             INT;
    v_minDuration            INTERVAL;
    v_nbStep                 INT;
    r_tbl                    RECORD;
    r_fk                     RECORD;
    r_batch                  RECORD;
  BEGIN
-- get the rollack characteristics for the emaj_rlbk event
    SELECT rlbk_groups, rlbk_mark, rlbk_is_logged, rlbk_nb_session,
           CASE WHEN rlbk_is_dblink_used THEN 'CTRL+DBLINK' ELSE 'CTRL-DBLINK' END
      INTO v_groupNames, v_mark, v_isLoggedRlbk, v_nbSession, v_ctrlStepName
      FROM emaj.emaj_rlbk WHERE rlbk_id = v_rlbkId;
-- get some mark attributes from emaj_mark
    SELECT mark_time_id INTO v_markTimeId
      FROM emaj.emaj_mark
      WHERE mark_group = v_groupNames[1] AND mark_name = v_mark;
-- get all duration parameters that will be needed later from the emaj_param table,
--   or get default values for rows that are not present in emaj_param table
    SELECT coalesce ((SELECT param_value_interval FROM emaj.emaj_param
                        WHERE param_key = 'avg_row_rollback_duration'),'100 microsecond'::interval),
           coalesce ((SELECT param_value_interval FROM emaj.emaj_param
                        WHERE param_key = 'avg_row_delete_log_duration'),'10 microsecond'::interval),
           coalesce ((SELECT param_value_interval FROM emaj.emaj_param
                        WHERE param_key = 'avg_fkey_check_duration'),'5 microsecond'::interval),
           coalesce ((SELECT param_value_interval FROM emaj.emaj_param
                        WHERE param_key = 'fixed_step_rollback_duration'),'2.5 millisecond'::interval),
           coalesce ((SELECT param_value_interval FROM emaj.emaj_param
                        WHERE param_key = 'fixed_dblink_rollback_duration'),'4 millisecond'::interval)
           INTO v_avg_row_rlbk, v_avg_row_del_log, v_avg_fkey_check, v_fixed_step_rlbk, v_fixed_dblink_rlbk;
-- insert into emaj_rlbk_plan a row per table belonging to the tables groups to process.
    INSERT INTO emaj.emaj_rlbk_plan (rlbp_rlbk_id, rlbp_step, rlbp_schema, rlbp_table, rlbp_fkey)
      SELECT v_rlbkId, 'LOCK_TABLE', rel_schema, rel_tblseq, ''
        FROM emaj.emaj_relation
        WHERE rel_group = ANY(v_groupNames) AND rel_kind = 'r';
-- insert into emaj_rlbk_plan a row per table to effectively rollback.
-- the numbers of log rows is computed using the _log_stat_tbl() function.
     INSERT INTO emaj.emaj_rlbk_plan
            (rlbp_rlbk_id, rlbp_step, rlbp_schema, rlbp_table, rlbp_fkey, rlbp_estimated_quantity)
      SELECT v_rlbkId, 'RLBK_TABLE', rel_schema, rel_tblseq, '',
             emaj._log_stat_tbl(t, v_markTimeId, NULL)
        FROM (SELECT * FROM emaj.emaj_relation
                WHERE rel_group = ANY (v_groupNames) AND rel_kind = 'r') AS t
        WHERE emaj._log_stat_tbl(t, v_markTimeId, NULL) > 0;
     GET DIAGNOSTICS v_effNbTable = ROW_COUNT;
--
-- group tables into batchs to process all tables linked by foreign keys as a batch
--
    v_batchNumber = 1;
--   allocate tables with rows to rollback to batch number starting with the heaviest to rollback tables
--     as reported by emaj_log_stat_group() function
    FOR r_tbl IN
        SELECT * FROM emaj.emaj_rlbk_plan
        WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'RLBK_TABLE' ORDER BY rlbp_estimated_quantity DESC
      LOOP
--   is the table already allocated to a batch number (it may have been already allocated because of a fkey link) ?
      PERFORM 0 FROM emaj.emaj_rlbk_plan
        WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'RLBK_TABLE'
          AND rlbp_schema = r_tbl.rlbp_schema AND rlbp_table = r_tbl.rlbp_table AND rlbp_batch_number IS NULL;
--   no,
      IF FOUND THEN
--   allocate the table to the batch number, with all other tables linked by foreign key constraints
        PERFORM emaj._rlbk_set_batch_number(v_rlbkId, v_batchNumber, r_tbl.rlbp_schema, r_tbl.rlbp_table);
        v_batchNumber = v_batchNumber + 1;
      END IF;
    END LOOP;
--
-- if unlogged rollback, register into emaj_rlbk_plan "disable log triggers", "deletes from log tables"
-- and "enable log trigger" steps
--
    IF NOT v_isLoggedRlbk THEN
-- compute the cost for each DIS_LOG_TRG step
--   if DIS_LOG_TRG statistics are available, compute an average cost
      SELECT sum(rlbt_duration) / sum(rlbt_quantity) INTO v_estimDuration FROM emaj.emaj_rlbk_stat
        WHERE rlbt_step = 'DIS_LOG_TRG';
      v_estimMethod = 2;
      IF v_estimDuration IS NULL THEN
--   otherwise, use the fixed_step_rollback_duration parameter
        v_estimDuration = v_fixed_step_rlbk;
        v_estimMethod = 3;
      END IF;
-- insert all DIS_LOG_TRG steps
      INSERT INTO emaj.emaj_rlbk_plan (
          rlbp_rlbk_id, rlbp_step, rlbp_schema, rlbp_table, rlbp_fkey, rlbp_batch_number,
          rlbp_estimated_duration, rlbp_estimate_method
        ) SELECT v_rlbkId, 'DIS_LOG_TRG', rlbp_schema, rlbp_table, '', rlbp_batch_number,
                 v_estimDuration, v_estimMethod
          FROM emaj.emaj_rlbk_plan
          WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'RLBK_TABLE';
-- insert all DELETE_LOG steps. But the duration estimates will be computed later
-- the estimated number of log rows to delete is set to the the estimated number of updates. This is underestimated
--   in particular when SQL UPDATES are logged. But the collected statistics used for duration estimates are also
--   based on the estimated number of updates.
      INSERT INTO emaj.emaj_rlbk_plan (
          rlbp_rlbk_id, rlbp_step, rlbp_schema, rlbp_table, rlbp_fkey, rlbp_batch_number, rlbp_estimated_quantity
        ) SELECT v_rlbkId, 'DELETE_LOG', rlbp_schema, rlbp_table, '', rlbp_batch_number, rlbp_estimated_quantity
          FROM emaj.emaj_rlbk_plan
          WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'RLBK_TABLE';
-- compute the cost for each ENA_LOG_TRG step
--   if DIS_LOG_TRG statistics are available, compute an average cost
      SELECT sum(rlbt_duration) / sum(rlbt_quantity) INTO v_estimDuration FROM emaj.emaj_rlbk_stat
        WHERE rlbt_step = 'ENA_LOG_TRG';
      v_estimMethod = 2;
      IF v_estimDuration IS NULL THEN
--   otherwise, use the fixed_step_rollback_duration parameter
        v_estimDuration = v_fixed_step_rlbk;
        v_estimMethod = 3;
      END IF;
-- insert all ENA_LOG_TRG steps
      INSERT INTO emaj.emaj_rlbk_plan (
          rlbp_rlbk_id, rlbp_step, rlbp_schema, rlbp_table, rlbp_fkey, rlbp_batch_number,
          rlbp_estimated_duration, rlbp_estimate_method
        ) SELECT v_rlbkId, 'ENA_LOG_TRG', rlbp_schema, rlbp_table, '', rlbp_batch_number,
                 v_estimDuration, v_estimMethod
          FROM emaj.emaj_rlbk_plan
          WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'RLBK_TABLE';
    END IF;
--
-- process foreign key to define which action to perform on them
--
-- First compute the fixed duration estimates for each 'DROP_FK' and 'SET_FK_DEF' steps
--   if DROP_FK statistics are available, compute an average cost
    SELECT sum(rlbt_duration) / sum(rlbt_quantity) INTO v_estimDropFkDuration FROM emaj.emaj_rlbk_stat
      WHERE rlbt_step = 'DROP_FK';
    v_estimDropFkMethod = 2;
    IF v_estimDropFkDuration IS NULL THEN
--   if no statistics are available for this step, use the fixed_step_rollback_duration parameter
      v_estimDropFkDuration = v_fixed_step_rlbk;
      v_estimDropFkMethod = 3;
    END IF;
--   if SET_FK_DEF statistics are available, compute an average cost
    SELECT sum(rlbt_duration) / sum(rlbt_quantity) INTO v_estimSetFkDefDuration FROM emaj.emaj_rlbk_stat
      WHERE rlbt_step = 'SET_FK_DEF';
    v_estimSetFkDefMethod = 2;
    IF v_estimSetFkDefDuration IS NULL THEN
--   if no statistics are available for this step, use the fixed_step_rollback_duration parameter
      v_estimSetFkDefDuration = v_fixed_step_rlbk;
      v_estimSetFkDefMethod = 3;
    END IF;
-- select all foreign keys belonging to or referencing the tables to process
    FOR r_fk IN
      SELECT c.oid AS conoid, c.conname, n.nspname, t.relname, t.reltuples, pg_get_constraintdef(c.oid) AS def, c.condeferrable, c.condeferred, c.confupdtype, c.confdeltype, r.rlbp_batch_number
        FROM pg_catalog.pg_constraint c, pg_catalog.pg_namespace n, pg_catalog.pg_class t, emaj.emaj_rlbk_plan r
        WHERE c.contype = 'f'                                            -- FK constraints only
          AND rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'RLBK_TABLE'       -- tables to rollback
          AND c.conrelid  = t.oid AND t.relnamespace  = n.oid            -- joins for table and namespace
          AND n.nspname = r.rlbp_schema AND t.relname = r.rlbp_table     -- join on emaj_rlbk_plan table
      UNION
      SELECT c.oid AS conoid, c.conname, n.nspname, t.relname, t.reltuples, pg_get_constraintdef(c.oid) AS def, c.condeferrable, c.condeferred, c.confupdtype, c.confdeltype, r.rlbp_batch_number
        FROM pg_catalog.pg_constraint c, pg_catalog.pg_namespace n, pg_catalog.pg_class t,
             pg_catalog.pg_namespace rn, pg_catalog.pg_class rt, emaj.emaj_rlbk_plan r
        WHERE c.contype = 'f'                                            -- FK constraints only
          AND rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'RLBK_TABLE'       -- tables to rollback
          AND c.conrelid  = t.oid AND t.relnamespace  = n.oid            -- joins for table and namespace
          AND c.confrelid  = rt.oid AND rt.relnamespace  = rn.oid        -- joins for referenced table and namespace
          AND rn.nspname = r.rlbp_schema AND rt.relname = r.rlbp_table   -- join on emaj_rlbk_plan table
      ORDER BY nspname, relname, conname
      LOOP
-- depending on the foreign key characteristics, record as 'to be dropped' or 'to be set deffered' or 'to just be reset immediate'
      IF NOT r_fk.condeferrable OR r_fk.confupdtype <> 'a' OR r_fk.confdeltype <> 'a' THEN
-- non deferrable fkeys and deferrable fkeys with an action for UPDATE or DELETE other than 'no action' need to be dropped
        INSERT INTO emaj.emaj_rlbk_plan (
          rlbp_rlbk_id, rlbp_step, rlbp_schema, rlbp_table, rlbp_fkey, rlbp_batch_number,
          rlbp_estimated_duration, rlbp_estimate_method
          ) VALUES (
          v_rlbkId, 'DROP_FK', r_fk.nspname, r_fk.relname, r_fk.conname, r_fk.rlbp_batch_number,
          v_estimDropFkDuration, v_estimDropFkMethod
          );
        INSERT INTO emaj.emaj_rlbk_plan (
          rlbp_rlbk_id, rlbp_step, rlbp_schema, rlbp_table, rlbp_fkey, rlbp_batch_number, rlbp_fkey_def, rlbp_estimated_quantity
          ) VALUES (
          v_rlbkId, 'ADD_FK', r_fk.nspname, r_fk.relname, r_fk.conname, r_fk.rlbp_batch_number, r_fk.def, r_fk.reltuples
          );
      ELSE
-- other deferrable but not deferred fkeys need to be set deferred
        IF NOT r_fk.condeferred THEN
          INSERT INTO emaj.emaj_rlbk_plan (
            rlbp_rlbk_id, rlbp_step, rlbp_schema, rlbp_table, rlbp_fkey, rlbp_batch_number,
            rlbp_estimated_duration, rlbp_estimate_method
            ) VALUES (
            v_rlbkId, 'SET_FK_DEF', r_fk.nspname, r_fk.relname, r_fk.conname, r_fk.rlbp_batch_number,
            v_estimSetFkDefDuration, v_estimSetFkDefMethod
            );
        END IF;
-- deferrable fkeys are recorded as 'to be set immediate at the end of the rollback operation'
-- compute the number of fkey values to check at set immediate time
        SELECT (coalesce(
--   get the number of rolled back rows in the referencing table, if any
           (SELECT rlbp_estimated_quantity
              FROM emaj.emaj_rlbk_plan
              WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'RLBK_TABLE'       -- tables of the rollback event
                AND rlbp_schema = r_fk.nspname AND rlbp_table = r_fk.relname)  -- referencing schema.table
            , 0)) + (coalesce(
--   get the number of rolled back rows in the referenced table, if any
           (SELECT rlbp_estimated_quantity
              FROM emaj.emaj_rlbk_plan, pg_catalog.pg_constraint c, pg_catalog.pg_namespace rn, pg_catalog.pg_class rt
              WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'RLBK_TABLE'       -- tables of the rollback event
                AND c.oid = r_fk.conoid                                        -- constraint id
                AND c.confrelid  = rt.oid AND rt.relnamespace  = rn.oid        -- joins for referenced schema.table
                AND rn.nspname = rlbp_schema AND rt.relname = rlbp_table)      -- join on emaj_rlbk_plan
            , 0)) INTO v_checks;
-- and record the SET_FK_IMM step
        INSERT INTO emaj.emaj_rlbk_plan (
          rlbp_rlbk_id, rlbp_step, rlbp_schema, rlbp_table, rlbp_fkey, rlbp_batch_number, rlbp_estimated_quantity
          ) VALUES (
          v_rlbkId, 'SET_FK_IMM', r_fk.nspname, r_fk.relname, r_fk.conname, r_fk.rlbp_batch_number, v_checks
          );
      END IF;
    END LOOP;
--
-- Now compute the estimation duration for each complex step ('RLBK_TABLE', 'DELETE_LOG', 'ADD_FK', 'SET_FK_IMM')
--
-- Compute the rollback duration estimates for the tables
-- for each table with content to rollback
    FOR r_tbl IN
        SELECT * FROM emaj.emaj_rlbk_plan
        WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'RLBK_TABLE'
      LOOP
-- first look at the previous rollback durations for the table and with similar rollback volume (same order of magnitude)
      SELECT sum(rlbt_duration) * r_tbl.rlbp_estimated_quantity / sum(rlbt_quantity) INTO v_estimDuration
        FROM emaj.emaj_rlbk_stat
        WHERE rlbt_step = 'RLBK_TABLE' AND rlbt_quantity > 0
          AND rlbt_schema = r_tbl.rlbp_schema AND rlbt_table = r_tbl.rlbp_table
          AND rlbt_quantity / r_tbl.rlbp_estimated_quantity < 10 AND r_tbl.rlbp_estimated_quantity / rlbt_quantity < 10;
      v_estimMethod = 1;
      IF v_estimDuration IS NULL THEN
-- if there is no previous rollback operation with similar volume, take statistics for the table with all available volumes
        SELECT sum(rlbt_duration) * r_tbl.rlbp_estimated_quantity / sum(rlbt_quantity) INTO v_estimDuration
          FROM emaj.emaj_rlbk_stat
          WHERE rlbt_step = 'RLBK_TABLE' AND rlbt_quantity > 0
            AND rlbt_schema = r_tbl.rlbp_schema AND rlbt_table = r_tbl.rlbp_table;
        v_estimMethod = 2;
        IF v_estimDuration IS NULL THEN
-- if there is no previous rollback operation, use the avg_row_rollback_duration from the emaj_param table
          v_estimDuration = v_avg_row_rlbk * r_tbl.rlbp_estimated_quantity + v_fixed_step_rlbk;
          v_estimMethod = 3;
        END IF;
      END IF;
      UPDATE emaj.emaj_rlbk_plan
        SET rlbp_estimated_duration = v_estimDuration, rlbp_estimate_method = v_estimMethod
        WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'RLBK_TABLE'
          AND rlbp_schema = r_tbl.rlbp_schema AND rlbp_table = r_tbl.rlbp_table;
    END LOOP;
-- Compute the log rows delete duration for the tables
    FOR r_tbl IN
        SELECT * FROM emaj.emaj_rlbk_plan
        WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'DELETE_LOG'
      LOOP
-- first look at the previous rollback durations for the table and with similar rollback volume (same order of magnitude)
      SELECT sum(rlbt_duration) * r_tbl.rlbp_estimated_quantity / sum(rlbt_quantity) INTO v_estimDuration
        FROM emaj.emaj_rlbk_stat
        WHERE rlbt_step = 'DELETE_LOG' AND rlbt_quantity > 0
          AND rlbt_schema = r_tbl.rlbp_schema AND rlbt_table = r_tbl.rlbp_table
          AND rlbt_quantity / r_tbl.rlbp_estimated_quantity < 10 AND r_tbl.rlbp_estimated_quantity / rlbt_quantity < 10;
      v_estimMethod = 1;
      IF v_estimDuration IS NULL THEN
-- if there is no previous rollback operation with similar volume, take statistics for the table with all available volumes
        SELECT sum(rlbt_duration) * r_tbl.rlbp_estimated_quantity / sum(rlbt_quantity) INTO v_estimDuration
          FROM emaj.emaj_rlbk_stat
          WHERE rlbt_step = 'DELETE_LOG' AND rlbt_quantity > 0
            AND rlbt_schema = r_tbl.rlbp_schema AND rlbt_table = r_tbl.rlbp_table;
        v_estimMethod = 2;
        IF v_estimDuration IS NULL THEN
-- if there is no previous rollback operation, use the avg_row_rollback_duration from the emaj_param table
          v_estimDuration = v_avg_row_del_log * r_tbl.rlbp_estimated_quantity + v_fixed_step_rlbk;
          v_estimMethod = 3;
        END IF;
      END IF;
      UPDATE emaj.emaj_rlbk_plan
        SET rlbp_estimated_duration = v_estimDuration, rlbp_estimate_method = v_estimMethod
        WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'DELETE_LOG'
          AND rlbp_schema = r_tbl.rlbp_schema AND rlbp_table = r_tbl.rlbp_table;
    END LOOP;
-- Compute the fkey recreation duration
    FOR r_fk IN
        SELECT * FROM emaj.emaj_rlbk_plan
        WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'ADD_FK'
      LOOP
      IF r_fk.rlbp_estimated_quantity = 0 THEN
-- empty table (or table not analyzed) => duration = 0
        v_estimDuration = 0;
        v_estimMethod = 3;
      ELSE
-- non empty table and statistics (with at least one row) are available
        SELECT sum(rlbt_duration) * r_fk.rlbp_estimated_quantity / sum(rlbt_quantity) INTO v_estimDuration
          FROM emaj.emaj_rlbk_stat
          WHERE rlbt_step = 'ADD_FK' AND rlbt_quantity > 0
            AND rlbt_schema = r_fk.rlbp_schema AND rlbt_table = r_fk.rlbp_table AND rlbt_fkey = r_fk.rlbp_fkey;
        v_estimMethod = 1;
        IF v_estimDuration IS NULL THEN
-- non empty table, but no statistics with at least one row are available => take the last duration for this fkey, if any
          SELECT rlbt_duration INTO v_estimDuration FROM emaj.emaj_rlbk_stat
            WHERE rlbt_step = 'ADD_FK'
              AND rlbt_schema = r_fk.rlbp_schema AND rlbt_table = r_tbl.rlbp_table AND rlbt_fkey = r_fk.rlbp_fkey
              AND rlbt_rlbk_id =
               (SELECT max(rlbt_rlbk_id) FROM emaj.emaj_rlbk_stat WHERE rlbt_step = 'ADD_FK'
                  AND rlbt_schema = r_fk.rlbp_schema AND rlbt_table = r_fk.rlbp_table AND rlbt_fkey = r_fk.rlbp_fkey);
          v_estimMethod = 2;
          IF v_estimDuration IS NULL THEN
-- definitely no statistics available, compute with the avg_fkey_check_duration parameter
            v_estimDuration = r_fk.rlbp_estimated_quantity * v_avg_fkey_check + v_fixed_step_rlbk;
            v_estimMethod = 3;
          END IF;
        END IF;
      END IF;
      UPDATE emaj.emaj_rlbk_plan
        SET rlbp_estimated_duration = v_estimDuration, rlbp_estimate_method = v_estimMethod
        WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'ADD_FK'
          AND rlbp_schema = r_fk.rlbp_schema AND rlbp_table = r_fk.rlbp_table AND rlbp_fkey = r_fk.rlbp_fkey;
    END LOOP;
-- Compute the fkey checks duration
    FOR r_fk IN
        SELECT * FROM emaj.emaj_rlbk_plan
        WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'SET_FK_IMM'
      LOOP
-- if fkey checks statistics are available for this fkey, compute an average cost
      SELECT sum(rlbt_duration) * r_fk.rlbp_estimated_quantity / sum(rlbt_quantity) INTO v_estimDuration
        FROM emaj.emaj_rlbk_stat
        WHERE rlbt_step = 'SET_FK_IMM' AND rlbt_quantity > 0
          AND rlbt_schema = r_fk.rlbp_schema AND rlbt_table = r_fk.rlbp_table AND rlbt_fkey = r_fk.rlbp_fkey;
      v_estimMethod = 2;
      IF v_estimDuration IS NULL THEN
-- if no statistics are available for this fkey, use the avg_fkey_check parameter
        v_estimDuration = r_fk.rlbp_estimated_quantity * v_avg_fkey_check + v_fixed_step_rlbk;
        v_estimMethod = 3;
      END IF;
      UPDATE emaj.emaj_rlbk_plan
        SET rlbp_estimated_duration = v_estimDuration, rlbp_estimate_method = v_estimMethod
        WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'SET_FK_IMM'
          AND rlbp_schema = r_fk.rlbp_schema AND rlbp_table = r_fk.rlbp_table AND rlbp_fkey = r_fk.rlbp_fkey;
    END LOOP;
--
-- Allocate batch number to sessions to spread the load on sessions as best as possible
-- A batch represents all steps related to the processing of one table or several tables linked by foreign keys
--
--   initialisation
    FOR v_session IN 1 .. v_nbSession LOOP
      v_sessionLoad [v_session] = 0;
    END LOOP;
--   allocate tables batch to sessions, starting with the heaviest to rollback batch
    FOR r_batch IN
        SELECT rlbp_batch_number, sum(rlbp_estimated_duration) AS batch_duration
          FROM emaj.emaj_rlbk_plan
          WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_batch_number IS NOT NULL
          GROUP BY rlbp_batch_number
          ORDER BY sum(rlbp_estimated_duration) DESC
      LOOP
--   compute the least loaded session
      v_minSession=1; v_minDuration = v_sessionLoad [1];
      FOR v_session IN 2 .. v_nbSession LOOP
        IF v_sessionLoad [v_session] < v_minDuration THEN
          v_minSession = v_session;
          v_minDuration = v_sessionLoad [v_session];
        END IF;
      END LOOP;
--   allocate the batch to the session
      UPDATE emaj.emaj_rlbk_plan SET rlbp_session = v_minSession
        WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_batch_number = r_batch.rlbp_batch_number;
      v_sessionLoad [v_minSession] = v_sessionLoad [v_minSession] + r_batch.batch_duration;
    END LOOP;
-- assign session 1 to all 'LOCK_TABLE' steps not yet affected
    UPDATE emaj.emaj_rlbk_plan SET rlbp_session = 1
      WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_session IS NULL;
-- Create the pseudo 'CTRL+DBLINK' or 'CTRL-DBLINK' step and compute its duration estimate
-- get the number of recorded steps (except LOCK_TABLE)
    SELECT count(*) INTO v_nbStep FROM emaj.emaj_rlbk_plan
      WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step <> 'LOCK_TABLE';
    IF v_nbStep > 0 THEN
-- if CTRLxDBLINK statistics are available, compute an average cost
      SELECT sum(rlbt_duration) * v_nbStep / sum(rlbt_quantity) INTO v_estimDuration
        FROM emaj.emaj_rlbk_stat WHERE rlbt_step = v_ctrlStepName AND rlbt_quantity > 0;
      v_estimMethod = 2;
      IF v_estimDuration IS NULL THEN
--   otherwise, use the fixed_step_rollback_duration parameter
        v_estimDuration = v_fixed_dblink_rlbk * v_nbStep;
        v_estimMethod = 3;
      END IF;
-- insert the 'CTRLxDBLINK' pseudo step
      INSERT INTO emaj.emaj_rlbk_plan (
          rlbp_rlbk_id, rlbp_step, rlbp_schema, rlbp_table, rlbp_fkey, rlbp_estimated_quantity,
          rlbp_estimated_duration, rlbp_estimate_method
        ) VALUES (
          v_rlbkId, v_ctrlStepName, '', '', '', v_nbStep, v_estimDuration, v_estimMethod
        );
    END IF;
-- return the number of tables to effectively rollback
    RETURN v_effNbTable;
  END;
$_rlbk_planning$;

CREATE OR REPLACE FUNCTION emaj._rlbk_session_lock(v_rlbkId INT, v_session INT)
RETURNS VOID LANGUAGE plpgsql AS
$_rlbk_session_lock$
-- It creates the session row in the emaj_rlbk_session table and then locks all the application tables for the session.
  DECLARE
    v_stmt                   TEXT;
    v_isDblinkUsable         BOOLEAN = false;
    v_groupNames             TEXT[];
    v_nbRetry                SMALLINT = 0;
    v_lockmode               TEXT;
    v_ok                     BOOLEAN = false;
    v_nbTbl                  INT;
    r_tbl                    RECORD;
  BEGIN
-- try to open a dblink connection for #session > 1 (the attempt for session 1 has already been done)
    IF v_session > 1 THEN
      PERFORM emaj._dblink_open_cnx('rlbk#'||v_session);
    END IF;
-- get the rollack characteristics for the emaj_rlbk
    SELECT rlbk_groups INTO v_groupNames FROM emaj.emaj_rlbk WHERE rlbk_id = v_rlbkId;
-- create the session row the emaj_rlbk_session table.
    v_stmt = 'INSERT INTO emaj.emaj_rlbk_session (rlbs_rlbk_id, rlbs_session, rlbs_txid, rlbs_start_datetime) ' ||
             'VALUES (' || v_rlbkId || ',' || v_session || ',' || txid_current() || ',' ||
              quote_literal(clock_timestamp()) || ') RETURNING 1';
    IF emaj._dblink_is_cnx_opened('rlbk#'||v_session) THEN
--    IF v_isDblinkUsable THEN
-- ... either through dblink if possible
      PERFORM 0 FROM dblink('rlbk#'||v_session,v_stmt) AS (dummy INT);
      v_isDblinkUsable = true;
    ELSE
-- ... or directly
      EXECUTE v_stmt;
    END IF;
-- insert lock begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('LOCK_GROUP', 'BEGIN', array_to_string(v_groupNames,','), 'Rollback session #' || v_session);
--
-- acquire locks on tables
--
-- in case of deadlock, retry up to 5 times
    WHILE NOT v_ok AND v_nbRetry < 5 LOOP
      BEGIN
        v_nbTbl = 0;
-- scan all tables of the session, in priority ascending order (priority being defined in emaj_group_def and stored in emaj_relation)
        FOR r_tbl IN
          SELECT quote_ident(rlbp_schema) || '.' || quote_ident(rlbp_table) AS fullName,
                 EXISTS (SELECT 1 FROM emaj.emaj_rlbk_plan rlbp2
                         WHERE rlbp2.rlbp_rlbk_id = v_rlbkId AND rlbp2.rlbp_session = v_session AND
                               rlbp2.rlbp_schema = rlbp1.rlbp_schema AND rlbp2.rlbp_table = rlbp1.rlbp_table AND
                               rlbp2.rlbp_step = 'DIS_LOG_TRG') AS disLogTrg
            FROM emaj.emaj_rlbk_plan rlbp1, emaj.emaj_relation
            WHERE rel_schema = rlbp_schema AND rel_tblseq = rlbp_table
            AND rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'LOCK_TABLE'
            AND rlbp_session = v_session
            ORDER BY rel_priority, rel_schema, rel_tblseq
            LOOP
--   lock each table
--     The locking level is EXCLUSIVE mode, except for tables whose log trigger needs to be disabled/enables when postgres version is prior 9.5.
--     In this later case, the ACCESS EXCLUSIVE mode is used, blocking all concurrent accesses to these tables.
--     In the former case, the EXCLUSIVE mode blocks all concurrent update capabilities of all tables of the groups (including tables with no logged
--     update to rollback), in order to ensure a stable state of the group at the end of the rollback operation). But these tables can be accessed
--     by SELECT statements during the E-Maj rollback.
          IF emaj._pg_version_num() < 90500 AND r_tbl.disLogTrg THEN
            v_lockmode = 'ACCESS EXCLUSIVE';
          ELSE
            v_lockmode = 'EXCLUSIVE';
          END IF;
          EXECUTE 'LOCK TABLE ' || r_tbl.fullName || ' IN ' || v_lockmode || ' MODE';
          v_nbTbl = v_nbTbl + 1;
        END LOOP;
-- ok, all tables locked
        v_ok = true;
      EXCEPTION
        WHEN deadlock_detected THEN
          v_nbRetry = v_nbRetry + 1;
          RAISE NOTICE '_rlbk_session_lock: a deadlock has been trapped while locking tables for groups "%".', array_to_string(v_groupNames,',');
      END;
    END LOOP;
    IF NOT v_ok THEN
      PERFORM emaj._rlbk_error(v_rlbkId, '_rlbk_session_lock: too many (5) deadlocks encountered while locking tables', v_session);
      RAISE EXCEPTION '_rlbk_session_lock: too many (5) deadlocks encountered while locking tables for groups "%".',array_to_string(v_groupNames,',');
    END IF;
-- insert end in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('LOCK_GROUP', 'END', array_to_string(v_groupNames,','), 'Rollback session #' || v_session || ': ' || v_nbTbl || ' tables locked, ' || v_nbRetry || ' deadlock(s)');
    RETURN;
-- trap and record exception during the rollback operation
  EXCEPTION
    WHEN SQLSTATE 'P0001' THEN             -- Do not trap the exceptions raised by the function
      RAISE;
    WHEN OTHERS THEN                       -- Otherwise, log the E-Maj rollback abort in emaj_rlbk, if possible
      PERFORM emaj._rlbk_error(v_rlbkId, 'In _rlbk_session_lock() for session ' || v_session || ': ' || SQLERRM, 'rlbk#'||v_session);
      RAISE;
  END;
$_rlbk_session_lock$;

CREATE OR REPLACE FUNCTION emaj._rlbk_start_mark(v_rlbkId INT, v_multiGroup BOOLEAN)
RETURNS VOID LANGUAGE plpgsql AS
$_rlbk_start_mark$
-- For logged rollback, it sets a mark that materialize the point in time just before the tables rollback.
-- All concerned tables are already locked.
-- Before setting the mark, it checks no update has been recorded between the planning step and the locks set
-- for tables for which no rollback was needed at planning time.
-- It also sets the rollback status to EXECUTING.
  DECLARE
    v_stmt                   TEXT;
    v_isDblinkUsable         BOOLEAN = false;
    v_timeId                 BIGINT;
    v_groupNames             TEXT[];
    v_mark                   TEXT;
    v_isLoggedRlbk           BOOLEAN;
    v_rlbkDatetime           TIMESTAMPTZ;
    v_markTimeId             BIGINT;
    v_markName               TEXT;
    v_errorMsg               TEXT;
  BEGIN
-- determine whether the dblink connection for this session is opened
    IF emaj._dblink_is_cnx_opened('rlbk#1') THEN
      v_isDblinkUsable = true;
    END IF;
-- get a time stamp for the rollback operation
    v_stmt = 'SELECT emaj._set_time_stamp(''R'')';
    IF v_isDblinkUsable THEN
-- ... either through dblink if possible
      SELECT time_id INTO v_timeId FROM dblink('rlbk#1',v_stmt) AS (time_id BIGINT);
    ELSE
-- ... or directly
      EXECUTE v_stmt INTO v_timeId;
    END IF;
-- update the emaj_rlbk table to record the time stamp and adjust the rollback status
    v_stmt = 'UPDATE emaj.emaj_rlbk SET rlbk_time_id = ' || v_timeId || ', rlbk_status = ''EXECUTING''' ||
             ' WHERE rlbk_id = ' || v_rlbkId || ' RETURNING 1';
    IF v_isDblinkUsable THEN
-- ... either through dblink if possible
      PERFORM 0 FROM dblink('rlbk#1',v_stmt) AS (dummy INT);
    ELSE
-- ... or directly
      EXECUTE v_stmt;
    END IF;
-- get the rollack characteristics for the emaj_rlbk
    SELECT rlbk_groups, rlbk_mark, rlbk_time_id, rlbk_is_logged, time_clock_timestamp
      INTO v_groupNames, v_mark, v_timeId, v_isLoggedRlbk, v_rlbkDatetime
      FROM emaj.emaj_rlbk, emaj.emaj_time_stamp WHERE rlbk_time_id = time_id AND rlbk_id = v_rlbkId;
-- get some mark attributes from emaj_mark
    SELECT mark_time_id INTO v_markTimeId
      FROM emaj.emaj_mark
      WHERE mark_group = v_groupNames[1] AND mark_name = v_mark;
-- check that no update has been recorded between planning time and lock time for tables that did not need to
-- be rolled back at planning time.
-- This may occur and cannot be avoided because tables cannot be locked before processing the rollback planning.
-- (Sessions must lock the tables they will rollback and the planning processing distribute those tables to sessions.)
    PERFORM 1 FROM (SELECT * FROM emaj.emaj_relation
                      WHERE rel_group = ANY (v_groupNames) AND rel_kind = 'r'
                        AND NOT EXISTS
                            (SELECT NULL FROM emaj.emaj_rlbk_plan
                              WHERE rlbp_schema = rel_schema AND rlbp_table = rel_tblseq
                                AND rlbp_rlbk_id = v_rlbkId AND rlbp_step = 'RLBK_TABLE')
                    ) AS t
      WHERE emaj._log_stat_tbl(t, v_markTimeId, NULL) > 0;
    IF FOUND THEN
      v_errorMsg = 'The rollback operation has been cancelled due to concurrent activity at E-Maj rollback planning time on tables to process.';
      PERFORM emaj._rlbk_error(v_rlbkId, v_errorMsg, 1);
      RAISE EXCEPTION '_rlbk_start_mark: % Please retry.', v_errorMsg;
    END IF;
    IF v_isLoggedRlbk THEN
-- If rollback is "logged" rollback, set a mark named with the pattern:
-- 'RLBK_<mark name to rollback to>_%_START', where % represents the rollback start time
      v_markName = 'RLBK_' || v_mark || '_' || to_char(v_rlbkDatetime, 'HH24.MI.SS.MS') || '_START';
      PERFORM emaj._set_mark_groups(v_groupNames, v_markName, v_multiGroup, true, NULL, v_timeId);
    END IF;
    RETURN;
-- trap and record exception during the rollback operation
  EXCEPTION
    WHEN SQLSTATE 'P0001' THEN             -- Do not trap the exceptions raised by the function
      RAISE;
    WHEN OTHERS THEN                       -- Otherwise, log the E-Maj rollback abort in emaj_rlbk, if possible
      PERFORM emaj._rlbk_error(v_rlbkId, 'In _rlbk_start_mark(): ' || SQLERRM, 'rlbk#1');
      RAISE;
  END;
$_rlbk_start_mark$;

CREATE OR REPLACE FUNCTION emaj._rlbk_session_exec(v_rlbkId INT, v_session INT)
RETURNS INT LANGUAGE plpgsql SECURITY DEFINER AS
$_rlbk_session_exec$
-- This function executes the main part of a rollback operation.
-- It executes the steps identified by _rlbk_planning() and stored into emaj_rlbk_plan, for one session.
-- The function returns the effective number of processed tables.
-- It updates the emaj_rlbk_plan table, using dblink connection if possible, giving a visibility of the rollback progress.
-- The function is defined as SECURITY DEFINER so that emaj_adm role can use it even if it doesn't own the application tables.
  DECLARE
    v_stmt                   TEXT;
    v_isDblinkUsable         BOOLEAN = false;
    v_effNbTable             INT = 0;
    v_groupNames             TEXT[];
    v_mark                   TEXT;
    v_rlbkMarkTimeId         BIGINT;
    v_rlbkTimeId             BIGINT;
    v_isLoggedRlbk           BOOLEAN;
    v_nbSession              INT;
    v_maxGlobalSeq           BIGINT;
    v_rlbkMarkId             BIGINT;
    v_lastGlobalSeq          BIGINT;
    v_nbRows                 BIGINT;
    r_step                   RECORD;
  BEGIN
-- determine whether the dblink connection for this session is opened
    IF emaj._dblink_is_cnx_opened('rlbk#'||v_session) THEN
      v_isDblinkUsable = true;
    END IF;
-- get the rollback characteristics from the emaj_rlbk table
    SELECT rlbk_groups, rlbk_mark, rlbk_time_id, rlbk_is_logged, rlbk_nb_session, time_last_emaj_gid
      INTO v_groupNames, v_mark, v_rlbkTimeId, v_isLoggedRlbk, v_nbSession, v_maxGlobalSeq
      FROM emaj.emaj_rlbk, emaj.emaj_time_stamp WHERE rlbk_id = v_rlbkId AND rlbk_time_id = time_id;
-- fetch the mark_id, the last global sequence at set_mark time for the first group of the groups array (they all share the same values - except for the mark_id)
    SELECT mark_id, mark_time_id, time_last_emaj_gid
      INTO v_rlbkMarkId, v_rlbkMarkTimeId, v_lastGlobalSeq
      FROM emaj.emaj_mark, emaj.emaj_time_stamp
      WHERE mark_time_id = time_id AND mark_group = v_groupNames[1] AND mark_name = v_mark;
-- scan emaj_rlbp_plan to get all steps to process that have been affected to this session, in batch_number and step order
    FOR r_step IN
      SELECT rlbp_step, rlbp_schema, rlbp_table, rlbp_fkey, rlbp_fkey_def
        FROM emaj.emaj_rlbk_plan,
             (VALUES ('DIS_LOG_TRG',1),('DROP_FK',2),('SET_FK_DEF',3),('RLBK_TABLE',4),
                     ('DELETE_LOG',5),('SET_FK_IMM',6),('ADD_FK',7),('ENA_LOG_TRG',8)) AS step(step_name, step_order)
        WHERE rlbp_step::text = step.step_name
          AND rlbp_rlbk_id = v_rlbkId AND rlbp_step NOT IN ('LOCK_TABLE','CTRL-DBLINK','CTRL+DBLINK')
          AND rlbp_session = v_session
        ORDER BY rlbp_batch_number, step_order, rlbp_table, rlbp_fkey
      LOOP
-- update the emaj_rlbk_plan table to set the step start time
      v_stmt = 'UPDATE emaj.emaj_rlbk_plan SET rlbp_start_datetime = clock_timestamp() ' ||
               ' WHERE rlbp_rlbk_id = ' || v_rlbkId || 'AND rlbp_step = ' || quote_literal(r_step.rlbp_step) ||
               ' AND rlbp_schema = ' || quote_literal(r_step.rlbp_schema) ||
               ' AND rlbp_table = ' || quote_literal(r_step.rlbp_table) ||
               ' AND rlbp_fkey = ' || quote_literal(r_step.rlbp_fkey) || ' RETURNING 1';
      IF v_isDblinkUsable THEN
-- ... either through dblink if possible
        PERFORM 0 FROM dblink('rlbk#'||v_session,v_stmt) AS (dummy INT);
      ELSE
-- ... or directly
        EXECUTE v_stmt;
      END IF;
-- process the step depending on its type
      CASE r_step.rlbp_step
        WHEN 'DIS_LOG_TRG' THEN
-- process a log trigger disable
          EXECUTE 'ALTER TABLE ' || quote_ident(r_step.rlbp_schema) || '.' || quote_ident(r_step.rlbp_table) ||
                  ' DISABLE TRIGGER emaj_log_trg';
        WHEN 'DROP_FK' THEN
-- process a foreign key deletion
          EXECUTE 'ALTER TABLE ' || quote_ident(r_step.rlbp_schema) || '.' || quote_ident(r_step.rlbp_table) ||
                  ' DROP CONSTRAINT ' || quote_ident(r_step.rlbp_fkey);
        WHEN 'SET_FK_DEF' THEN
-- set a foreign key deferred
          EXECUTE 'SET CONSTRAINTS ' || quote_ident(r_step.rlbp_schema) || '.' || quote_ident(r_step.rlbp_fkey) ||
                  ' DEFERRED';
        WHEN 'RLBK_TABLE' THEN
-- process a table rollback
          SELECT emaj._rlbk_tbl(emaj_relation.*, v_lastGlobalSeq, v_maxGlobalSeq, v_nbSession, v_isLoggedRlbk) INTO v_nbRows
            FROM emaj.emaj_relation
            WHERE rel_schema = r_step.rlbp_schema AND rel_tblseq = r_step.rlbp_table;
          v_effNbTable = v_effNbTable + 1;
        WHEN 'DELETE_LOG' THEN
-- process the deletion of log rows
          SELECT emaj._delete_log_tbl(emaj_relation.*, v_rlbkMarkTimeId, v_rlbkTimeId, v_lastGlobalSeq)
            INTO v_nbRows
            FROM emaj.emaj_relation
            WHERE rel_schema = r_step.rlbp_schema AND rel_tblseq = r_step.rlbp_table;
        WHEN 'SET_FK_IMM' THEN
-- set a foreign key immediate
          EXECUTE 'SET CONSTRAINTS ' || quote_ident(r_step.rlbp_schema) || '.' || quote_ident(r_step.rlbp_fkey) ||
                  ' IMMEDIATE';
        WHEN 'ADD_FK' THEN
-- process a foreign key creation
          EXECUTE 'ALTER TABLE ' || quote_ident(r_step.rlbp_schema) || '.' || quote_ident(r_step.rlbp_table) ||
                  ' ADD CONSTRAINT ' || quote_ident(r_step.rlbp_fkey) || ' ' || r_step.rlbp_fkey_def;
        WHEN 'ENA_LOG_TRG' THEN
-- process a log trigger enable
          EXECUTE 'ALTER TABLE ' || quote_ident(r_step.rlbp_schema) || '.' || quote_ident(r_step.rlbp_table) ||
                  ' ENABLE TRIGGER emaj_log_trg';
      END CASE;
-- update the emaj_rlbk_plan table to set the step duration
-- NB: the computed duration does not include the time needed to update the emaj_rlbk_plan table
      v_stmt = 'UPDATE emaj.emaj_rlbk_plan SET rlbp_duration = ' || quote_literal(clock_timestamp()) || ' - rlbp_start_datetime';
      IF r_step.rlbp_step = 'RLBK_TABLE' OR r_step.rlbp_step = 'DELETE_LOG' THEN
--   and the effective number of processed rows for RLBK_TABLE and DELETE_LOG steps
        v_stmt = v_stmt || ' , rlbp_quantity = ' || v_nbRows;
      END IF;
      v_stmt = v_stmt ||
               ' WHERE rlbp_rlbk_id = ' || v_rlbkId || 'AND rlbp_step = ' || quote_literal(r_step.rlbp_step) ||
               ' AND rlbp_schema = ' || quote_literal(r_step.rlbp_schema) ||
               ' AND rlbp_table = ' || quote_literal(r_step.rlbp_table) ||
               ' AND rlbp_fkey = ' || quote_literal(r_step.rlbp_fkey) || ' RETURNING 1';
      IF v_isDblinkUsable THEN
-- ... either through dblink if possible
        PERFORM 0 FROM dblink('rlbk#'||v_session,v_stmt) AS (dummy INT);
      ELSE
-- ... or directly
        EXECUTE v_stmt;
      END IF;
    END LOOP;
-- update the emaj_rlbk_session table to set the timestamp representing the end of work for the session
    v_stmt = 'UPDATE emaj.emaj_rlbk_session SET rlbs_end_datetime = clock_timestamp()' ||
             ' WHERE rlbs_rlbk_id = ' || v_rlbkId || ' AND rlbs_session = ' || v_session ||
             ' RETURNING 1';
    IF v_isDblinkUsable THEN
-- ... either through dblink if possible
      PERFORM 0 FROM dblink('rlbk#'||v_session,v_stmt) AS (dummy INT);
--     and then close the connection for session > 1
      IF v_session > 1 THEN
        PERFORM emaj._dblink_close_cnx('rlbk#'||v_session);
      END IF;
    ELSE
-- ... or directly
      EXECUTE v_stmt;
    END IF;
    RETURN v_effNbTable;
-- trap and record exception during the rollback operation
  EXCEPTION
    WHEN SQLSTATE 'P0001' THEN             -- Do not trap the exceptions raised by the function
      RAISE;
    WHEN OTHERS THEN                       -- Otherwise, log the E-Maj rollback abort in emaj_rlbk, if possible
      PERFORM emaj._rlbk_error(v_rlbkId, 'In _rlbk_session_exec() for session ' || v_session || ': ' || SQLERRM, 'rlbk#'||v_session);
      RAISE;
  END;
$_rlbk_session_exec$;

CREATE OR REPLACE FUNCTION emaj._rlbk_end(v_rlbkId INT, v_multiGroup BOOLEAN)
RETURNS INT LANGUAGE plpgsql AS
$_rlbk_end$
-- This is the last step of a rollback group processing. It :
--    - deletes the marks that are no longer available,
--    - deletes the recorded sequences values for these deleted marks
--    - copy data into the emaj_rlbk_stat table,
--    - rollbacks all sequences of the groups,
--    - set the end rollback mark if logged rollback,
--    - and finaly set the operation as COMPLETED or COMMITED.
-- It returns the number of processed sequences.
  DECLARE
    v_stmt                   TEXT;
    v_isDblinkUsable         BOOLEAN = false;
    v_groupNames             TEXT[];
    v_mark                   TEXT;
    v_isLoggedRlbk           BOOLEAN;
    v_rlbkDatetime           TIMESTAMPTZ;
    v_effNbTbl               INT;
    v_ctrlDuration           INTERVAL;
    v_markId                 BIGINT;
    v_markTimeId             BIGINT;
    v_nbSeq                  INT;
    v_markName               TEXT;
    v_histDateTime           TIMESTAMPTZ;
  BEGIN
-- determine whether the dblink connection for this session is opened
    IF emaj._dblink_is_cnx_opened('rlbk#1') THEN
      v_isDblinkUsable = true;
    END IF;
-- get the rollack characteristics for the emaj_rlbk
    SELECT rlbk_groups, rlbk_mark, rlbk_is_logged, rlbk_eff_nb_table, time_clock_timestamp
      INTO v_groupNames, v_mark, v_isLoggedRlbk, v_effNbTbl, v_rlbkDatetime
      FROM emaj.emaj_rlbk, emaj.emaj_time_stamp WHERE rlbk_time_id = time_id AND  rlbk_id = v_rlbkId;
-- get the mark timestamp for the 1st group (they all share the same timestamp)
    SELECT mark_time_id INTO v_markTimeId FROM emaj.emaj_mark
      WHERE mark_group = v_groupNames[1] AND mark_name = v_mark;
-- if "unlogged" rollback, delete all marks later than the now rolled back mark and the associated sequences
    IF NOT v_isLoggedRlbk THEN
-- get the highest mark id of the mark used for rollback, for all groups
      SELECT max(mark_id) INTO v_markId
        FROM emaj.emaj_mark WHERE mark_group = ANY (v_groupNames) AND mark_name = v_mark;
-- delete the marks that are suppressed by the rollback (the related sequences have been already deleted by rollback functions)
-- with a logging in the history
      WITH deleted AS (
        DELETE FROM emaj.emaj_mark
          WHERE mark_group = ANY (v_groupNames) AND mark_id > v_markId
          RETURNING mark_time_id, mark_group, mark_name),
           sorted_deleted AS (                                       -- the sort is performed to produce stable results in regression tests
        SELECT mark_group, mark_name FROM deleted ORDER BY mark_time_id, mark_group)
      INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
        SELECT CASE WHEN v_multiGroup THEN 'ROLLBACK_GROUPS' ELSE 'ROLLBACK_GROUP' END,
               'MARK DELETED', mark_group, 'mark ' || mark_name || ' is deleted' FROM sorted_deleted;
-- and reset the mark_log_rows_before_next column for the new last mark
      UPDATE emaj.emaj_mark SET mark_log_rows_before_next = NULL
        WHERE mark_group = ANY (v_groupNames)
          AND (mark_group, mark_id) IN                -- select only the last non deleted mark of each concerned group
              (SELECT mark_group, MAX(mark_id) FROM emaj.emaj_mark
               WHERE mark_group = ANY (v_groupNames) AND NOT mark_is_deleted GROUP BY mark_group);
-- the sequences related to the deleted marks can be also suppressed
--   delete first application sequences related data for the groups
      DELETE FROM emaj.emaj_sequence USING emaj.emaj_relation
        WHERE rel_group = ANY (v_groupNames) AND rel_kind = 'S'
          AND sequ_schema = rel_schema AND sequ_name = rel_tblseq
          AND sequ_time_id > v_markTimeId;
--   delete then emaj sequences related data for the groups
      DELETE FROM emaj.emaj_sequence USING emaj.emaj_relation
        WHERE rel_group = ANY (v_groupNames) AND rel_kind = 'r'
          AND sequ_schema = rel_log_schema AND sequ_name = rel_log_sequence
          AND sequ_time_id > v_markTimeId;
    END IF;
-- delete the now useless 'LOCK TABLE' steps from the emaj_rlbk_plan table
    v_stmt = 'DELETE FROM emaj.emaj_rlbk_plan ' ||
             ' WHERE rlbp_rlbk_id = ' || v_rlbkId || ' AND rlbp_step = ''LOCK_TABLE'' RETURNING 1';
    IF v_isDblinkUsable THEN
-- ... either through dblink if possible
      PERFORM 0 FROM dblink('rlbk#1',v_stmt) AS (dummy INT);
    ELSE
-- ... or directly
      EXECUTE v_stmt;
    END IF;
-- Prepare the CTRLxDBLINK pseudo step statistic by computing the global time spent between steps
    SELECT coalesce(sum(ctrl_duration),'0'::interval) INTO v_ctrlDuration FROM (
      SELECT rlbs_session, rlbs_end_datetime - min(rlbp_start_datetime) - sum(rlbp_duration) AS ctrl_duration
        FROM emaj.emaj_rlbk_session rlbs, emaj.emaj_rlbk_plan rlbp
        WHERE rlbp_rlbk_id = rlbs_rlbk_id AND rlbp_session = rlbs_session
          AND rlbs_rlbk_id = v_rlbkID
        GROUP BY rlbs_session, rlbs_end_datetime ) AS t;
-- report duration statistics into the emaj_rlbk_stat table
    v_stmt = 'INSERT INTO emaj.emaj_rlbk_stat (rlbt_step, rlbt_schema, rlbt_table, rlbt_fkey,' ||
             '      rlbt_rlbk_id, rlbt_quantity, rlbt_duration)' ||
--   copy elementary steps for RLBK_TABLE, DELETE_LOG, ADD_FK and SET_FK_IMM step types
--     (record the rlbp_estimated_quantity as reference for later forecast)
             '  SELECT rlbp_step, rlbp_schema, rlbp_table, rlbp_fkey, rlbp_rlbk_id,' ||
             '      rlbp_estimated_quantity, rlbp_duration' ||
             '    FROM emaj.emaj_rlbk_plan, emaj.emaj_rlbk' ||
             '    WHERE rlbk_id = rlbp_rlbk_id AND rlbp_rlbk_id = ' || v_rlbkId ||
             '      AND rlbp_step IN (''RLBK_TABLE'',''DELETE_LOG'',''ADD_FK'',''SET_FK_IMM'') ' ||
             '  UNION ALL ' ||
--   for 4 other steps, aggregate other elementary steps into a global row for each step type
             '  SELECT rlbp_step, '''', '''', '''', rlbp_rlbk_id, ' ||
             '      count(*), sum(rlbp_duration)' ||
             '    FROM emaj.emaj_rlbk_plan, emaj.emaj_rlbk' ||
             '    WHERE rlbk_id = rlbp_rlbk_id AND rlbp_rlbk_id = ' || v_rlbkId ||
             '      AND rlbp_step IN (''DIS_LOG_TRG'',''DROP_FK'',''SET_FK_DEF'',''ENA_LOG_TRG'') ' ||
             '    GROUP BY 1, 2, 3, 4, 5' ||
             '  UNION ALL ' ||
--   and the final CTRLxDBLINK pseudo step statistic
             '  SELECT rlbp_step, '''', '''', '''', rlbp_rlbk_id, ' ||
             '      rlbp_estimated_quantity, ' || quote_literal(v_ctrlDuration) ||
             '    FROM emaj.emaj_rlbk_plan, emaj.emaj_rlbk' ||
             '    WHERE rlbk_id = rlbp_rlbk_id AND rlbp_rlbk_id = ' || v_rlbkId ||
             '      AND rlbp_step IN (''CTRL+DBLINK'',''CTRL-DBLINK'') ' ||
             ' RETURNING 1';
    IF v_isDblinkUsable THEN
-- ... either through dblink if possible
      PERFORM 0 FROM dblink('rlbk#1',v_stmt) AS (dummy INT);
    ELSE
-- ... or directly
      EXECUTE v_stmt;
    END IF;
-- rollback the application sequences belonging to the groups
-- warning, this operation is not transaction safe (that's why it is placed at the end of the operation)!
    PERFORM emaj._rlbk_seq(t.*, v_markTimeId)
      FROM (SELECT * FROM emaj.emaj_relation
              WHERE rel_group = ANY (v_groupNames) AND rel_kind = 'S'
              ORDER BY rel_priority, rel_schema, rel_tblseq) as t;
    GET DIAGNOSTICS v_nbSeq = ROW_COUNT;
-- if rollback is "logged" rollback, automaticaly set a mark representing the tables state just after the rollback.
-- this mark is named 'RLBK_<mark name to rollback to>_%_DONE', where % represents the rollback start time
    IF v_isLoggedRlbk THEN
      v_markName = 'RLBK_' || v_mark || '_' || to_char(v_rlbkDatetime, 'HH24.MI.SS.MS') || '_DONE';
      PERFORM emaj._set_mark_groups(v_groupNames, v_markName, v_multiGroup, true, v_mark);
    END IF;
-- insert end in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES (CASE WHEN v_multiGroup THEN 'ROLLBACK_GROUPS' ELSE 'ROLLBACK_GROUP' END, 'END',
              array_to_string(v_groupNames,','),
              'Rollback_id ' || v_rlbkId || ', ' || v_effNbTbl || ' tables and ' || v_nbSeq || ' sequences effectively processed'
             ) RETURNING hist_datetime INTO v_histDateTime;
-- update the emaj_rlbk table to set the real number of tables to process, adjust the rollback status and set the result message
    IF v_isDblinkUsable THEN
-- ... either through dblink if possible
      v_stmt = 'UPDATE emaj.emaj_rlbk SET rlbk_status = ''COMPLETED'', rlbk_end_datetime = ' ||
               quote_literal(v_histDateTime) || ', rlbk_msg = ''Completed: ' ||
               v_effNbTbl || ' tables and ' || v_nbSeq || ' sequences effectively processed''' ||
               ' WHERE rlbk_id = ' || v_rlbkId || ' RETURNING 1';
      PERFORM 0 FROM dblink('rlbk#1',v_stmt) AS (dummy INT);
--     and then close the connection
      PERFORM emaj._dblink_close_cnx('rlbk#1');
    ELSE
-- ... or directly (the status can be directly set to committed, the update being in the same transaction)
      EXECUTE 'UPDATE emaj.emaj_rlbk SET rlbk_status = ''COMMITTED'', rlbk_end_datetime = ' ||
               quote_literal(v_histDateTime) || ', rlbk_msg = ''Completed: ' ||
               v_effNbTbl || ' tables and ' || v_nbSeq || ' sequences effectively processed''' ||
               ' WHERE rlbk_id = ' || v_rlbkId;
    END IF;
    RETURN v_nbSeq;
-- trap and record exception during the rollback operation
  EXCEPTION
    WHEN SQLSTATE 'P0001' THEN             -- Do not trap the exceptions raised by the function
      RAISE;
    WHEN OTHERS THEN                       -- Otherwise, log the E-Maj rollback abort in emaj_rlbk, if possible
      PERFORM emaj._rlbk_error(v_rlbkId, 'In _rlbk_end(): ' || SQLERRM, 'rlbk#1');
      RAISE;
  END;
$_rlbk_end$;

CREATE OR REPLACE FUNCTION emaj._rlbk_error(v_rlbkId INT, v_msg TEXT, v_cnxName TEXT)
RETURNS VOID LANGUAGE plpgsql AS
$_rlbk_error$
-- This function records a rollback error into the emaj_rlbk table, but only if a dblink connection is open
-- Input: rollback identifier, message to record and dblink connection name
-- If the rollback operation is already in aborted state, one keeps the emaj_rlbk data unchanged
  DECLARE
    v_stmt                   TEXT;
  BEGIN
    IF emaj._dblink_is_cnx_opened(v_cnxName) THEN
      v_stmt = 'UPDATE emaj.emaj_rlbk SET rlbk_status = ''ABORTED'', rlbk_msg = ' || quote_literal(v_msg) ||
               ', rlbk_end_datetime =  clock_timestamp() ' ||
               'WHERE rlbk_id = ' || v_rlbkId || ' AND rlbk_status <> ''ABORTED'' RETURNING 1';
      PERFORM 0 FROM dblink(v_cnxName,v_stmt) AS (dummy INT);
    END IF;
    RETURN;
  END;
$_rlbk_error$;

CREATE OR REPLACE FUNCTION emaj.emaj_consolidate_rollback_group(v_groupName TEXT, v_endRlbkMark TEXT)
RETURNS BIGINT LANGUAGE plpgsql SECURITY DEFINER AS
$emaj_consolidate_rollback_group$
-- This function "consolidates" a rollback for a group. It transforms an already completed logged rollback into an unlogged rollback.
-- All marks and update logs between a mark used as reference by an unlogged rollback operation and the final mark set by this rollback are suppressed.
-- The group may be in any state (logging or idle).
-- Input: group name, name of the final mark set by the rollback operation to consolidate
-- Output: number of sequences and tables effectively processed
  DECLARE
    v_firstMark              TEXT;
    v_lastMark               TEXT;
    v_nbMark                 INT;
    v_nbSeq                  INT;
    v_nbTbl                  INT;
  BEGIN
-- check and lock the group to process
    SELECT group_nb_sequence INTO v_nbSeq FROM emaj.emaj_group WHERE group_name = v_groupName FOR UPDATE;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_consolidate_rollback_group: group "%" has not been created.', v_groupName;
    END IF;
-- retrieve and check the mark name
    SELECT emaj._get_mark_name(v_groupName,v_endRlbkMark) INTO v_lastMark;
    IF v_lastMark IS NULL THEN
      RAISE EXCEPTION 'emaj_consolidate_rollback_group: mark "%" does not exist for group "%".', v_endRlbkMark, v_groupName;
    END IF;
-- check that no group is damaged
    PERFORM 0 FROM emaj._verify_groups(ARRAY[v_groupName], true);
-- check the supplied mark is known as an end rollback mark
    SELECT mark_logged_rlbk_target_mark INTO v_firstMark FROM emaj.emaj_mark
      WHERE mark_group = v_groupName AND mark_name = v_lastMark;
    IF v_firstMark IS NULL THEN
      RAISE EXCEPTION 'emaj_consolidate_rollback_group: mark "%" for group "%" is not an end rollback mark.', v_lastMark, v_groupName;
    END IF;
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('CONSOLIDATE_RLBK_GROUP', 'BEGIN', v_groupName, 'Erase all between marks ' || v_firstMark || ' and ' || v_lastMark);
-- check the first mark really exists (it should, because deleting or renaming a mark must update the mark_logged_rlbk_mark_name column)
    PERFORM 1 FROM emaj.emaj_mark WHERE mark_group = v_groupName AND mark_name = v_firstMark;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_consolidate_rollback_group: rollback target mark "%" for group "%" has not been found.', v_firstMark, v_groupName;
    END IF;
-- perform the consolidation operation
    SELECT * FROM emaj._delete_between_marks_group(v_groupName, v_firstMark, v_lastMark) INTO v_nbMark,v_nbTbl;
-- insert end in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('CONSOLIDATE_RLBK_GROUP', 'END', v_groupName, v_nbTbl || ' tables and ' || v_nbSeq || ' sequences processed ; ' || v_nbMark || ' marks deleted');
    RETURN v_nbTbl + v_nbSeq;
  END;
$emaj_consolidate_rollback_group$;
COMMENT ON FUNCTION emaj.emaj_consolidate_rollback_group(TEXT,TEXT) IS
$$Consolidate a rollback for a group.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_get_consolidable_rollbacks()
RETURNS SETOF emaj.emaj_consolidable_rollback_type LANGUAGE plpgsql AS
$emaj_get_consolidable_rollbacks$
-- This function returns the list of logged rollback operations that can be consolidated, defined as a marks range for a group.
-- It doesn't need input parameter.
-- It returns a set of emaj_consolidable_rollback_type records, sorted by ascending rollback time.
-- The cons_group and cons_end_rlbk_mark_name returned columns can be used as input parameters for the emaj_consolidate_rollback_group() function.
  DECLARE
    r_mark                   RECORD;
  BEGIN
-- search all marks range corresponding to any logged rollback operation
    FOR r_mark IN
      SELECT m1.mark_group AS cons_group,
             m2.mark_name AS cons_target_rlbk_mark_name, m2.mark_id AS cons_target_rlbk_mark_id,
             m1.mark_name AS cons_end_rlbk_mark_name, m1.mark_id AS cons_end_rlbk_mark_id,
             cast(0 AS BIGINT) AS cons_rows, cast(0 AS INT) as cons_marks
        FROM emaj.emaj_mark m1
          JOIN emaj.emaj_mark m2 ON (m2.mark_name = m1.mark_logged_rlbk_target_mark AND m2.mark_group = m1.mark_group)
          WHERE m1.mark_logged_rlbk_target_mark IS NOT NULL
          ORDER BY m1.mark_id
      LOOP
-- compute the number of updates for this mark range
      SELECT cast(sum(stat_rows) AS BIGINT) INTO r_mark.cons_rows
        FROM emaj.emaj_log_stat_group(r_mark.cons_group, r_mark.cons_target_rlbk_mark_name, r_mark.cons_end_rlbk_mark_name);
-- compute the number of intermediate marks for this mark range
      SELECT count(*) INTO r_mark.cons_marks FROM emaj.emaj_mark
        WHERE mark_group = r_mark.cons_group AND mark_id > r_mark.cons_target_rlbk_mark_id AND mark_id < r_mark.cons_end_rlbk_mark_id;
-- and return a row
      RETURN NEXT r_mark;
    END LOOP;
-- TODO: When postgres 9.2- will not be supported anymore, the following statement with a LATERAL clause will be usable to replace the loop
--    RETURN QUERY
--      SELECT m1.mark_group AS cons_group, m2.mark_name AS cons_target_rlbk_mark_name, m2.mark_id AS cons_target_rlbk_mark_id,
--             m1.mark_name AS cons_end_rlbk_mark_name, m1.mark_id AS cons_end_rlbk_mark_id, cast(sum(stat_rows) AS BIGINT) AS cons_rows,
--             cast((SELECT count(*) FROM emaj.emaj_mark m3
--                   WHERE m3.mark_group = m1.mark_group AND m3.mark_id > m2.mark_id AND m3.mark_id < m1.mark_id) AS INT) AS cons_marks
--        FROM emaj.emaj_mark m1
--          JOIN emaj.emaj_mark m2 ON (m2.mark_name = m1.mark_logged_rlbk_target_mark AND m2.mark_group = m1.mark_group)
--          LEFT OUTER JOIN LATERAL emaj.emaj_log_stat_group(m1.mark_group, m1.mark_logged_rlbk_target_mark, m1.mark_name) ON TRUE
--          WHERE m1.mark_logged_rlbk_target_mark IS NOT NULL
--          GROUP BY 1,2,3,4,5
--          ORDER BY m1.mark_id;
  END;
$emaj_get_consolidable_rollbacks$;
COMMENT ON FUNCTION emaj.emaj_get_consolidable_rollbacks() IS
$$Returns the list of logged rollback operations that can be consolidated.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_reset_group(v_groupName TEXT)
RETURNS INT LANGUAGE plpgsql SECURITY DEFINER AS
$emaj_reset_group$
-- This function empties the log tables for all tables of a group and deletes the sequences saves
-- It calls the emaj_rst_group function to do the job
-- Input: group name
-- Output: number of processed tables
-- The function is defined as SECURITY DEFINER so that emaj_adm role can use it even if he is not the owner of application tables.
  DECLARE
    v_groupIsLogging         BOOLEAN;
    v_nbTb                   INT = 0;
  BEGIN
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object)
      VALUES ('RESET_GROUP', 'BEGIN', v_groupName);
-- check that the group is recorded in emaj_group table
    SELECT group_is_logging INTO v_groupIsLogging
      FROM emaj.emaj_group WHERE group_name = v_groupName FOR UPDATE;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_reset_group: group "%" has not been created.', v_groupName;
    END IF;
-- check that the group is not in LOGGING state
    IF v_groupIsLogging THEN
      RAISE EXCEPTION 'emaj_reset_group: Group "%" cannot be reset because it is in LOGGING state. An emaj_stop_group function must be previously executed.', v_groupName;
    END IF;
-- perform the reset operation
    SELECT emaj._reset_group(v_groupName) INTO v_nbTb;
    IF v_nbTb = 0 THEN
       RAISE EXCEPTION 'emaj_reset_group: internal error (group "%" is empty).', v_groupName;
    END IF;
-- insert end in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('RESET_GROUP', 'END', v_groupName, v_nbTb || ' tables/sequences processed');
    RETURN v_nbTb;
  END;
$emaj_reset_group$;
COMMENT ON FUNCTION emaj.emaj_reset_group(TEXT) IS
$$Resets all log tables content of a stopped E-Maj group.$$;

CREATE OR REPLACE FUNCTION emaj._reset_group(v_groupName TEXT)
RETURNS INT LANGUAGE plpgsql SECURITY DEFINER AS
$_reset_group$
-- This function empties the log tables for all tables of a group, using a TRUNCATE, and deletes the sequences saves
-- It is called by both emaj_reset_group and emaj_start_group functions
-- Input: group name
-- Output: number of processed tables and sequences
-- There is no check of the group state
-- The function is defined as SECURITY DEFINER so that an emaj_adm role can truncate log tables
  DECLARE
    v_nbTb                   INT;
    r_rel                    RECORD;
  BEGIN
-- delete all marks for the group from the emaj_mark table
    DELETE FROM emaj.emaj_mark WHERE mark_group = v_groupName;
-- delete emaj_sequence rows related to the tables of the group
    DELETE FROM emaj.emaj_sequence USING emaj.emaj_relation
      WHERE rel_group = v_groupName AND rel_kind = 'r' AND sequ_schema = rel_log_schema AND sequ_name = rel_log_sequence;
-- delete all sequence holes for the tables of the group
    DELETE FROM emaj.emaj_seq_hole USING emaj.emaj_relation
      WHERE rel_group = v_groupName AND rel_kind = 'r' AND rel_schema = sqhl_schema AND rel_tblseq = sqhl_table;
-- initialize the return value with the number of sequences
    SELECT count(*) INTO v_nbTb FROM emaj.emaj_relation
      WHERE rel_group = v_groupName AND rel_kind = 'S';
-- delete emaj_sequence rows related to the sequences of the group
    PERFORM emaj._drop_seq(emaj_relation.*) FROM emaj.emaj_relation
      WHERE rel_group = v_groupName AND rel_kind = 'S';
-- then, truncate log tables for application tables
    FOR r_rel IN
        SELECT rel_log_schema, rel_log_table, rel_log_sequence FROM emaj.emaj_relation
          WHERE rel_group = v_groupName AND rel_kind = 'r'
          ORDER BY rel_priority, rel_schema, rel_tblseq
        LOOP
--   truncate the log table
      EXECUTE 'TRUNCATE ' || quote_ident(r_rel.rel_log_schema) || '.' || quote_ident(r_rel.rel_log_table);
--   and reset the log sequence
      PERFORM setval(quote_ident(r_rel.rel_log_schema) || '.' || quote_ident(r_rel.rel_log_sequence), 1, false);
      v_nbTb = v_nbTb + 1;
    END LOOP;
    RETURN v_nbTb;
  END;
$_reset_group$;

CREATE OR REPLACE FUNCTION emaj.emaj_log_stat_group(v_groupName TEXT, v_firstMark TEXT, v_lastMark TEXT)
RETURNS SETOF emaj.emaj_log_stat_type LANGUAGE plpgsql AS
$emaj_log_stat_group$
-- This function returns statistics on row updates executed between 2 marks or between a mark and the current situation.
-- It is used to quickly get simple statistics of updates logged between 2 marks (i.e. for one or several processing)
-- It is also used to estimate the cost of a rollback to a specified mark
-- These statistics are computed using the serial id of log tables and holes is sequences recorded into emaj_seq_hole at rollback time
-- Input: group name, the 2 mark names defining a range
--   a NULL value or an empty string as first_mark indicates the first recorded mark
--   a NULL value or an empty string as last_mark indicates the current situation
--   Use a NULL or an empty string as last_mark to know the number of rows to rollback to reach the mark specified by the first_mark parameter.
--   The keyword 'EMAJ_LAST_MARK' can be used as first or last mark to specify the last set mark.
-- Output: table of log rows by table (including tables with 0 rows to rollback)
  DECLARE
    v_realFirstMark          TEXT;
    v_realLastMark           TEXT;
    v_firstMarkId            BIGINT;
    v_lastMarkId             BIGINT;
    v_firstMarkTimeId        BIGINT;
    v_lastMarkTimeId         BIGINT;
    v_firstMarkTs            TIMESTAMPTZ;
    v_lastMarkTs             TIMESTAMPTZ;
  BEGIN
-- check that the group is recorded in emaj_group table
    PERFORM 0 FROM emaj.emaj_group WHERE group_name = v_groupName;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_log_stat_group: group "%" has not been created.', v_groupName;
    END IF;
-- if first mark is NULL or empty, retrieve the name, timestamp and last sequ_hole id of the first recorded mark for the group
    IF v_firstMark IS NULL OR v_firstMark = '' THEN
--   if no mark exists for the group (just after emaj_create_group() or emaj_reset_group() functions call),
--     v_realFirstMark remains NULL
      SELECT mark_name, mark_id, mark_time_id, time_clock_timestamp INTO v_realFirstMark, v_firstMarkId, v_firstMarkTimeId, v_firstMarkTs
        FROM emaj.emaj_mark, emaj.emaj_time_stamp
        WHERE time_id = mark_time_id AND mark_group = v_groupName
        ORDER BY mark_id LIMIT 1;
    ELSE
-- else, check and retrieve the name, timestamp and last sequ_hole id of the supplied first mark for the group
      SELECT emaj._get_mark_name(v_groupName,v_firstMark) INTO v_realFirstMark;
      IF v_realFirstMark IS NULL THEN
        RAISE EXCEPTION 'emaj_log_stat_group: Start mark "%" is unknown for group "%".', v_firstMark, v_groupName;
      END IF;
      SELECT mark_id, mark_time_id, time_clock_timestamp INTO v_firstMarkId, v_firstMarkTimeId, v_firstMarkTs
        FROM emaj.emaj_mark, emaj.emaj_time_stamp
        WHERE time_id = mark_time_id AND mark_group = v_groupName AND mark_name = v_realFirstMark;
    END IF;
-- if a last mark name is supplied, check and retrieve the name, timestamp and last sequ_hole id of the supplied end mark for the group
    IF v_lastMark IS NOT NULL AND v_lastMark <> '' THEN
      SELECT emaj._get_mark_name(v_groupName,v_lastMark) INTO v_realLastMark;
      IF v_realLastMark IS NULL THEN
        RAISE EXCEPTION 'emaj_log_stat_group: End mark "%" is unknown for group "%".', v_lastMark, v_groupName;
      END IF;
      SELECT mark_id, mark_time_id, time_clock_timestamp INTO v_lastMarkId, v_lastMarkTimeId, v_lastMarkTs
        FROM emaj.emaj_mark, emaj.emaj_time_stamp
        WHERE time_id = mark_time_id AND mark_group = v_groupName AND mark_name = v_realLastMark;
-- if last mark is null or empty, v_realLastMark, v_lastMarkTimeId, v_lastMarkTs and v_lastLastSeqHoleId remain NULL
    END IF;
-- check that the first_mark < end_mark
    IF v_lastMarkTimeId IS NOT NULL AND v_firstMarkTimeId > v_lastMarkTimeId THEN
      RAISE EXCEPTION 'emaj_log_stat_group: mark id for "%" (% = %) is greater than mark id for "%" (% = %).', v_firstMark, v_firstMarkId, v_firstMarkTs, v_lastMark,  v_lastMarkId, v_lastMarkTs;
    END IF;
-- for each table of the emaj_relation table, get the number of log rows and return the statistic
    RETURN QUERY
      SELECT rel_group, rel_schema, rel_tblseq,
             CASE WHEN v_firstMarkTimeId IS NULL THEN 0
                  ELSE emaj._log_stat_tbl(emaj_relation, v_firstMarkTimeId, v_lastMarkTimeId) END AS nb_rows
        FROM emaj.emaj_relation
        WHERE rel_group = v_groupName AND rel_kind = 'r' ORDER BY rel_priority, rel_schema, rel_tblseq;
  END;
$emaj_log_stat_group$;
COMMENT ON FUNCTION emaj.emaj_log_stat_group(TEXT,TEXT,TEXT) IS
$$Returns global statistics about logged events for an E-Maj group between 2 marks.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_detailed_log_stat_group(v_groupName TEXT, v_firstMark TEXT, v_lastMark TEXT)
RETURNS SETOF emaj.emaj_detailed_log_stat_type LANGUAGE plpgsql AS
$emaj_detailed_log_stat_group$
-- This function returns statistics on row updates executed between 2 marks as viewed through the log tables
-- It provides more information than emaj_log_stat_group but it needs to scan log tables in order to provide these data.
-- So the response time may be much longer.
-- Input: group name, the 2 marks names defining a range
--   a NULL value or an empty string as first_mark indicates the first recorded mark
--   a NULL value or an empty string as last_mark indicates the current situation
--   The keyword 'EMAJ_LAST_MARK' can be used as first or last mark to specify the last set mark.
-- Output: table of updates by user and table
  DECLARE
    v_realFirstMark          TEXT;
    v_realLastMark           TEXT;
    v_firstMarkId            BIGINT;
    v_lastMarkId             BIGINT;
    v_firstMarkTs            TIMESTAMPTZ;
    v_lastMarkTs             TIMESTAMPTZ;
    v_firstEmajGid           BIGINT;
    v_lastEmajGid            BIGINT;
    v_logTableName           TEXT;
    v_stmt                   TEXT;
    r_tblsq                  RECORD;
    r_stat                   RECORD;
  BEGIN
-- check that the group is recorded in emaj_group table
    PERFORM 0 FROM emaj.emaj_group WHERE group_name = v_groupName;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_detailed_log_stat_group: group "%" has not been created.', v_groupName;
    END IF;
-- catch the timestamp of the first mark
    IF v_firstMark IS NOT NULL AND v_firstMark <> '' THEN
-- check and retrieve the global sequence value and the timestamp of the start mark for the group
      SELECT emaj._get_mark_name(v_groupName,v_firstMark) INTO v_realFirstMark;
      IF v_realFirstMark IS NULL THEN
          RAISE EXCEPTION 'emaj_detailed_log_stat_group: Start mark "%" is unknown for group "%".', v_firstMark, v_groupName;
      END IF;
      SELECT mark_id, time_last_emaj_gid, time_clock_timestamp INTO v_firstMarkId, v_firstEmajGid, v_firstMarkTs
        FROM emaj.emaj_mark, emaj.emaj_time_stamp
        WHERE mark_time_id = time_id AND mark_group = v_groupName AND mark_name = v_realFirstMark;
    END IF;
-- catch the timestamp of the last mark
    IF v_lastMark IS NOT NULL AND v_lastMark <> '' THEN
-- else, check and retrieve the global sequence value and the timestamp of the end mark for the group
      SELECT emaj._get_mark_name(v_groupName,v_lastMark) INTO v_realLastMark;
      IF v_realLastMark IS NULL THEN
        RAISE EXCEPTION 'emaj_detailed_log_stat_group: End mark "%" is unknown for group "%".', v_lastMark, v_groupName;
      END IF;
      SELECT mark_id, time_last_emaj_gid, time_clock_timestamp INTO v_lastMarkId, v_lastEmajGid, v_lastMarkTs
        FROM emaj.emaj_mark, emaj.emaj_time_stamp
        WHERE mark_time_id = time_id AND mark_group = v_groupName AND mark_name = v_realLastMark;
    END IF;
-- check that the first_mark < end_mark
    IF v_realFirstMark IS NOT NULL AND v_realLastMark IS NOT NULL AND v_firstMarkId > v_lastMarkId THEN
      RAISE EXCEPTION 'emaj_detailed_log_stat_group: mark id for "%" (% = %) is greater than mark id for "%" (% = %).', v_realFirstMark, v_firstMarkId, v_firstMarkTs, v_realLastMark, v_lastMarkId, v_lastMarkTs;
    END IF;
-- for each table of the emaj_relation table
    FOR r_tblsq IN
        SELECT rel_priority, rel_schema, rel_tblseq, rel_log_schema, rel_kind, rel_log_table FROM emaj.emaj_relation
          WHERE rel_group = v_groupName AND rel_kind = 'r'
          ORDER BY rel_priority, rel_schema, rel_tblseq
        LOOP
-- count the number of operations per type (INSERT, UPDATE and DELETE) and role
-- compute the log table name and its sequence name for this table
      v_logTableName = quote_ident(r_tblsq.rel_log_schema) || '.' || quote_ident(r_tblsq.rel_log_table);
-- prepare and execute the statement
      v_stmt= 'SELECT ' || quote_literal(v_groupName) || '::TEXT as emaj_group,'
           || ' ' || quote_literal(r_tblsq.rel_schema) || '::TEXT as emaj_schema,'
           || ' ' || quote_literal(r_tblsq.rel_tblseq) || '::TEXT as emaj_table,'
           || ' emaj_user,'
           || ' CASE WHEN emaj_verb = ''INS'' THEN ''INSERT'''
           ||      ' WHEN emaj_verb = ''UPD'' THEN ''UPDATE'''
           ||      ' WHEN emaj_verb = ''DEL'' THEN ''DELETE'''
           ||      ' ELSE ''?'' END::VARCHAR(6) as emaj_verb,'
           || ' count(*) as emaj_rows'
           || ' FROM ' || v_logTableName
           || ' WHERE NOT (emaj_verb = ''UPD'' AND emaj_tuple = ''OLD'')';
      IF v_firstMark IS NOT NULL AND v_firstMark <> '' THEN v_stmt = v_stmt
           || ' AND emaj_gid > '|| v_firstEmajGid ;
      END IF;
      IF v_lastMark IS NOT NULL AND v_lastMark <> '' THEN v_stmt = v_stmt
           || ' AND emaj_gid <= '|| v_lastEmajGid ;
      END IF;
      v_stmt = v_stmt
           || ' GROUP BY emaj_group, emaj_schema, emaj_table, emaj_user, emaj_verb'
           || ' ORDER BY emaj_user, emaj_verb';
      FOR r_stat IN EXECUTE v_stmt LOOP
        RETURN NEXT r_stat;
      END LOOP;
    END LOOP;
    RETURN;
  END;
$emaj_detailed_log_stat_group$;
COMMENT ON FUNCTION emaj.emaj_detailed_log_stat_group(TEXT,TEXT,TEXT) IS
$$Returns detailed statistics about logged events for an E-Maj group between 2 marks.$$;

CREATE OR REPLACE FUNCTION emaj._estimate_rollback_groups(v_groupNames TEXT[], v_mark TEXT, v_isLoggedRlbk BOOLEAN)
RETURNS INTERVAL LANGUAGE plpgsql SECURITY DEFINER AS
$_estimate_rollback_groups$
-- This function effectively computes an approximate duration of a rollback to a predefined mark for a groups array.
-- It simulates a rollback on 1 session, by calling the _rlbk_planning function that already estimates elementary
-- rollback steps duration. Once the global estimate is got, the rollback planning is cancelled.
-- Input: a group names array, the mark name of the rollback operation, the rollback type.
-- Output: the approximate duration that the rollback would need as time interval.
-- The function is declared SECURITY DEFINER so that emaj_viewer doesn't need a specific INSERT permission on emaj_rlbk.
  DECLARE
    v_markName               TEXT;
    v_fixed_table_rlbk       INTERVAL;
    v_rlbkId                 INT;
    v_estimDuration          INTERVAL;
    v_nbTblseq               INT;
  BEGIN
-- check supplied group names and mark parameters
    SELECT emaj._rlbk_check(v_groupNames, v_mark) INTO v_markName;
-- compute a random negative rollback-id (not to interfere with ids of real rollbacks)
    SELECT (random() * -2147483648)::int INTO v_rlbkId;
--
-- simulate a rollback planning
--
    BEGIN
-- insert a row into the emaj_rlbk table for this simulated rollback operation
      INSERT INTO emaj.emaj_rlbk (rlbk_id, rlbk_groups, rlbk_mark, rlbk_mark_time_id, rlbk_is_logged, rlbk_nb_session)
        VALUES (v_rlbkId, v_groupNames, v_mark, emaj._get_mark_time_id(v_groupNames[1], v_markName), v_isLoggedRlbk, 1);
-- call the _rlbk_planning function
      PERFORM emaj._rlbk_planning(v_rlbkId);
-- compute the sum of the duration estimates of all elementary steps (except LOCK_TABLE)
      SELECT coalesce(sum(rlbp_estimated_duration), '0 SECONDS'::INTERVAL) INTO v_estimDuration
        FROM emaj.emaj_rlbk_plan
        WHERE rlbp_rlbk_id = v_rlbkId AND rlbp_step <> 'LOCK_TABLE';
-- cancel the effect of the rollback planning
      RAISE EXCEPTION '';
    EXCEPTION
      WHEN RAISE_EXCEPTION THEN                 -- catch the raised exception and continue
    END;
-- get the "fixed_table_rollback_duration" parameter from the emaj_param table
    SELECT coalesce ((SELECT param_value_interval FROM emaj.emaj_param
                        WHERE param_key = 'fixed_table_rollback_duration'),'1 millisecond'::interval)
           INTO v_fixed_table_rlbk;
-- get the the number of tables to lock and sequences to rollback
    SELECT sum(group_nb_table)+sum(group_nb_sequence) INTO v_nbTblseq
      FROM emaj.emaj_group
      WHERE group_name = ANY(v_groupNames);
-- compute the final estimated duration
    v_estimDuration = v_estimDuration + (v_nbTblseq * v_fixed_table_rlbk);
    RETURN v_estimDuration;
  END;
$_estimate_rollback_groups$;

CREATE OR REPLACE FUNCTION emaj._rollback_activity()
RETURNS SETOF emaj.emaj_rollback_activity_type LANGUAGE plpgsql AS
$_rollback_activity$
-- This function effectively builds the list of rollback operations currently in execution.
-- It is called by the emaj_rollback_activity() function.
-- This is a separate function to help in testing the feature (avoiding the effects of emaj_cleanup_rollback_state()).
-- The number of parallel rollback sessions is not taken into account here,
--   as it is difficult to estimate the benefit brought by several parallel sessions.
-- The times and progression indicators reported are based on the transaction timestamp (allowing stable results in regression tests).
  DECLARE
    v_ipsDuration            INTERVAL;           -- In Progress Steps Duration
    v_nyssDuration           INTERVAL;           -- Not Yes Started Steps Duration
    v_nbNyss                 INT;                -- Number of Net Yes Started Steps
    v_ctrlDuration           INTERVAL;
    v_currentTotalEstimate   INTERVAL;
    r_rlbk                   emaj.emaj_rollback_activity_type;
  BEGIN
-- retrieve all not completed rollback operations (ie in 'PLANNING', 'LOCKING' or 'EXECUTING' state)
    FOR r_rlbk IN
      SELECT rlbk_id, rlbk_groups, rlbk_mark, t1.time_clock_timestamp, rlbk_is_logged, rlbk_nb_session,
             rlbk_nb_table, rlbk_nb_sequence, rlbk_eff_nb_table, rlbk_status, t2.time_tx_timestamp,
             transaction_timestamp() - t2.time_tx_timestamp AS "elapse", NULL, 0
        FROM emaj.emaj_rlbk
             JOIN emaj.emaj_time_stamp t1 ON (rlbk_mark_time_id = t1.time_id)
             LEFT OUTER JOIN emaj.emaj_time_stamp t2 ON (rlbk_time_id = t2.time_id)
        WHERE rlbk_status IN ('PLANNING', 'LOCKING', 'EXECUTING')
        ORDER BY rlbk_id
        LOOP
-- compute the estimated remaining duration
--   for rollback operations in 'PLANNING' state, the remaining duration is NULL
      IF r_rlbk.rlbk_status IN ('LOCKING', 'EXECUTING') THEN
--     estimated duration of remaining work of in progress steps
        SELECT coalesce(
               sum(CASE WHEN rlbp_start_datetime + rlbp_estimated_duration - transaction_timestamp() > '0'::interval
                        THEN rlbp_start_datetime + rlbp_estimated_duration - transaction_timestamp()
                        ELSE '0'::interval END),'0'::interval) INTO v_ipsDuration
          FROM emaj.emaj_rlbk_plan WHERE rlbp_rlbk_id = r_rlbk.rlbk_id
           AND rlbp_start_datetime IS NOT NULL AND rlbp_duration IS NULL;
--     estimated duration and number of not yet started steps
        SELECT coalesce(sum(rlbp_estimated_duration),'0'::interval), count(*) INTO v_nyssDuration, v_nbNyss
          FROM emaj.emaj_rlbk_plan WHERE rlbp_rlbk_id = r_rlbk.rlbk_id
           AND rlbp_start_datetime IS NULL
           AND rlbp_step NOT IN ('CTRL-DBLINK','CTRL+DBLINK');
--     estimated duration of inter-step duration for not yet started steps
        SELECT coalesce(sum(rlbp_estimated_duration) * v_nbNyss / sum(rlbp_estimated_quantity),'0'::interval)
          INTO v_ctrlDuration
          FROM emaj.emaj_rlbk_plan WHERE rlbp_rlbk_id = r_rlbk.rlbk_id
           AND rlbp_step IN ('CTRL-DBLINK','CTRL+DBLINK');
--     update the global remaining duration estimate
        r_rlbk.rlbk_remaining = v_ipsDuration + v_nyssDuration + v_ctrlDuration;
      END IF;
-- compute the completion pct
--   for rollback operations in 'PLANNING' or 'LOCKING' state, the completion_pct = 0
      IF r_rlbk.rlbk_status = 'EXECUTING' THEN
--   first compute the new total duration estimate, using the estimate of the remaining work
        SELECT transaction_timestamp() - time_tx_timestamp + r_rlbk.rlbk_remaining INTO v_currentTotalEstimate
          FROM emaj.emaj_rlbk, emaj.emaj_time_stamp
          WHERE rlbk_time_id = time_id AND rlbk_id = r_rlbk.rlbk_id;
--   and then the completion pct
        IF v_currentTotalEstimate <> '0'::interval THEN
          SELECT 100 - (extract(epoch FROM r_rlbk.rlbk_remaining) * 100
                      / extract(epoch FROM v_currentTotalEstimate))::smallint
            INTO r_rlbk.rlbk_completion_pct;
        END IF;
      END IF;
      RETURN NEXT r_rlbk;
    END LOOP;
    RETURN;
  END;
$_rollback_activity$;

CREATE OR REPLACE FUNCTION emaj.emaj_snap_group(v_groupName TEXT, v_dir TEXT, v_copyOptions TEXT)
RETURNS INT LANGUAGE plpgsql SECURITY DEFINER AS
$emaj_snap_group$
-- This function creates a file for each table and sequence belonging to the group.
-- For tables, these files contain all rows sorted on primary key.
-- For sequences, they contain a single row describing the sequence.
-- To do its job, the function performs COPY TO statement, with all default parameters.
-- For table without primary key, rows are sorted on all columns.
-- There is no need for the group not to be logging.
-- As all COPY statements are executed inside a single transaction:
--   - the function can be called while other transactions are running,
--   - the snap files will present a coherent state of tables.
-- It's users responsability :
--   - to create the directory (with proper permissions allowing the cluster to write into) before
-- emaj_snap_group function call, and
--   - maintain its content outside E-maj.
-- Input: group name, the absolute pathname of the directory where the files are to be created and the options to used in the COPY TO statements
-- Output: number of processed tables and sequences
-- The function is defined as SECURITY DEFINER so that emaj_adm role can use.
  DECLARE
    v_nbTb                   INT = 0;
    r_tblsq                  RECORD;
    v_fullTableName          TEXT;
    v_colList                TEXT;
    v_fileName               TEXT;
    v_stmt                   TEXT;
  BEGIN
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('SNAP_GROUP', 'BEGIN', v_groupName, v_dir);
-- check that the group is recorded in emaj_group table
    PERFORM 0 FROM emaj.emaj_group WHERE group_name = v_groupName;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_snap_group: group "%" has not been created.', v_groupName;
    END IF;
-- check the supplied directory is not null
    IF v_dir IS NULL THEN
      RAISE EXCEPTION 'emaj_snap_group: directory parameter cannot be NULL';
    END IF;
-- check the copy options parameter doesn't contain unquoted ; that could be used for sql injection
    IF regexp_replace(v_copyOptions,'''.*''','') LIKE '%;%' THEN
      RAISE EXCEPTION 'emaj_snap_group: invalid COPY options parameter format';
    END IF;
-- for each table/sequence of the emaj_relation table
    FOR r_tblsq IN
        SELECT rel_priority, rel_schema, rel_tblseq, rel_kind FROM emaj.emaj_relation
          WHERE rel_group = v_groupName ORDER BY rel_priority, rel_schema, rel_tblseq
        LOOP
      v_fileName = v_dir || '/' || r_tblsq.rel_schema || '_' || r_tblsq.rel_tblseq || '.snap';
      v_fullTableName = quote_ident(r_tblsq.rel_schema) || '.' || quote_ident(r_tblsq.rel_tblseq);
      CASE r_tblsq.rel_kind
        WHEN 'r' THEN
-- if it is a table,
--   first build the order by column list
          PERFORM 0 FROM pg_catalog.pg_class, pg_catalog.pg_namespace, pg_catalog.pg_constraint
            WHERE relnamespace = pg_namespace.oid AND connamespace = pg_namespace.oid AND conrelid = pg_class.oid AND
                  contype = 'p' AND nspname = r_tblsq.rel_schema AND relname = r_tblsq.rel_tblseq;
          IF FOUND THEN
--   the table has a pkey,
            SELECT string_agg(quote_ident(attname), ',') INTO v_colList FROM (
              SELECT attname FROM pg_catalog.pg_attribute, pg_catalog.pg_index
                WHERE pg_attribute.attrelid = pg_index.indrelid
                  AND attnum = ANY (indkey)
                  AND indrelid = v_fullTableName::regclass AND indisprimary
                  AND attnum > 0 AND attisdropped = false) AS t;
          ELSE
--   the table has no pkey
            SELECT string_agg(quote_ident(attname), ',') INTO v_colList FROM (
              SELECT attname FROM pg_catalog.pg_attribute
                WHERE attrelid = v_fullTableName::regclass
                  AND attnum > 0  AND attisdropped = false) AS t;
          END IF;
--   prepare the COPY statement
          v_stmt= 'COPY (SELECT * FROM ' || v_fullTableName || ' ORDER BY ' || v_colList || ') TO ' ||
                  quote_literal(v_fileName) || ' ' || coalesce (v_copyOptions, '');
        WHEN 'S' THEN
-- if it is a sequence, the statement has no order by
          v_stmt= 'COPY (SELECT sequence_name, last_value, start_value, increment_by, max_value, ' ||
                  'min_value, cache_value, is_cycled, is_called FROM ' || v_fullTableName || ') TO ' ||
                  quote_literal(v_fileName) || ' ' || coalesce (v_copyOptions, '');
      END CASE;
-- and finaly perform the COPY
      EXECUTE v_stmt;
      v_nbTb = v_nbTb + 1;
    END LOOP;
-- create the _INFO file to keep general information about the snap operation
    EXECUTE 'COPY (SELECT ' ||
            quote_literal('E-Maj snap of tables group ' || v_groupName ||
            ' at ' || transaction_timestamp()) ||
            ') TO ' || quote_literal(v_dir || '/_INFO');
-- insert end in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('SNAP_GROUP', 'END', v_groupName, v_nbTb || ' tables/sequences processed');
    RETURN v_nbTb;
  END;
$emaj_snap_group$;
COMMENT ON FUNCTION emaj.emaj_snap_group(TEXT,TEXT,TEXT) IS
$$Snaps all application tables and sequences of an E-Maj group into a given directory.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_snap_log_group(v_groupName TEXT, v_firstMark TEXT, v_lastMark TEXT, v_dir TEXT, v_copyOptions TEXT)
RETURNS INT LANGUAGE plpgsql SECURITY DEFINER AS
$emaj_snap_log_group$
-- This function creates a file for each log table belonging to the group.
-- It also creates 2 files containing the state of sequences respectively at start mark and end mark
-- For log tables, files contain all rows related to the time frame, sorted on emaj_gid.
-- For sequences, files are names <group>_sequences_at_<mark>, or <group>_sequences_at_<time> if no
--   end mark is specified. They contain one row per sequence.
-- To do its job, the function performs COPY TO statement, using the options provided by the caller.
-- There is no need for the group not to be logging.
-- As all COPY statements are executed inside a single transaction:
--   - the function can be called while other transactions are running,
--   - the snap files will present a coherent state of tables.
-- It's users responsability :
--   - to create the directory (with proper permissions allowing the cluster to write into) before
-- emaj_snap_log_group function call, and
--   - maintain its content outside E-maj.
-- Input: group name, the 2 mark names defining a range, the absolute pathname of the directory where the files are to be created, options for COPY TO statements
--   a NULL value or an empty string as first_mark indicates the first recorded mark
--   a NULL value or an empty string can be used as last_mark indicating the current state
--   The keyword 'EMAJ_LAST_MARK' can be used as first or last mark to specify the last set mark.
-- Output: number of processed tables and sequences
-- The function is defined as SECURITY DEFINER so that emaj_adm role can use.
  DECLARE
    v_nbTb                   INT = 0;
    r_tblsq                  RECORD;
    v_realFirstMark          TEXT;
    v_realLastMark           TEXT;
    v_firstMarkId            BIGINT;
    v_lastMarkId             BIGINT;
    v_firstEmajGid           BIGINT;
    v_lastEmajGid            BIGINT;
    v_firstMarkTsId          BIGINT;
    v_lastMarkTsId           BIGINT;
    v_firstMarkTs            TIMESTAMPTZ;
    v_lastMarkTs             TIMESTAMPTZ;
    v_logTableName           TEXT;
    v_fileName               TEXT;
    v_conditions             TEXT;
    v_stmt                   TEXT;
  BEGIN
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('SNAP_LOG_GROUP', 'BEGIN', v_groupName,
       CASE WHEN v_firstMark IS NULL OR v_firstMark = '' THEN 'From initial mark' ELSE 'From mark ' || v_firstMark END ||
       CASE WHEN v_lastMark IS NULL OR v_lastMark = '' THEN ' to current situation' ELSE ' to mark ' || v_lastMark END || ' towards '
       || v_dir);
-- check that the group is recorded in emaj_group table
    PERFORM 0 FROM emaj.emaj_group WHERE group_name = v_groupName;
    IF NOT FOUND THEN
      RAISE EXCEPTION 'emaj_snap_log_group: group "%" has not been created.', v_groupName;
    END IF;
-- check the supplied directory is not null
    IF v_dir IS NULL THEN
      RAISE EXCEPTION 'emaj_snap_log_group: directory parameter cannot be NULL';
    END IF;
-- check the copy options parameter doesn't contain unquoted ; that could be used for sql injection
    IF regexp_replace(v_copyOptions,'''.*''','') LIKE '%;%'  THEN
      RAISE EXCEPTION 'emaj_snap_log_group: invalid COPY options parameter format';
    END IF;
-- catch the global sequence value and the timestamp of the first mark
    IF v_firstMark IS NOT NULL AND v_firstMark <> '' THEN
-- check and retrieve the global sequence value and the timestamp of the start mark for the group
      SELECT emaj._get_mark_name(v_groupName,v_firstMark) INTO v_realFirstMark;
      IF v_realFirstMark IS NULL THEN
          RAISE EXCEPTION 'emaj_snap_log_group: Start mark "%" is unknown for group "%".', v_firstMark, v_groupName;
      END IF;
      SELECT mark_id, time_id, time_last_emaj_gid, time_clock_timestamp
        INTO v_firstMarkId, v_firstMarkTsId, v_firstEmajGid, v_firstMarkTs
        FROM emaj.emaj_mark, emaj.emaj_time_stamp
        WHERE mark_time_id = time_id AND mark_group = v_groupName AND mark_name = v_realFirstMark;
    ELSE
      SELECT mark_name, mark_id, time_id, time_last_emaj_gid, time_clock_timestamp
        INTO v_realFirstMark, v_firstMarkId, v_firstMarkTsId, v_firstEmajGid, v_firstMarkTs
        FROM emaj.emaj_mark, emaj.emaj_time_stamp
        WHERE mark_time_id = time_id AND mark_group = v_groupName ORDER BY mark_id LIMIT 1;
    END IF;
    IF v_lastMark IS NOT NULL AND v_lastMark <> '' THEN
-- the end mark is supplied
      SELECT emaj._get_mark_name(v_groupName,v_lastMark) INTO v_realLastMark;
      IF v_realLastMark IS NULL THEN
        RAISE EXCEPTION 'emaj_snap_log_group: End mark "%" is unknown for group "%".', v_lastMark, v_groupName;
      END IF;
    ELSE
-- the end mark is not supplied (look for the current state)
-- temporarily create a mark, without locking tables
      SELECT emaj._check_new_mark('TEMP_%', ARRAY[v_groupName]) INTO v_realLastMark;
      PERFORM emaj._set_mark_groups(ARRAY[v_groupName], v_realLastMark, false, false);
    END IF;
-- catch the global sequence value and timestamp of the last mark
    SELECT mark_id, time_id, time_last_emaj_gid, time_clock_timestamp INTO v_lastMarkId, v_lastMarkTsId, v_lastEmajGid, v_lastMarkTs
      FROM emaj.emaj_mark, emaj.emaj_time_stamp
      WHERE mark_time_id = time_id AND mark_group = v_groupName AND mark_name = v_realLastMark;
-- check that the first_mark < end_mark
    IF v_firstMarkId > v_lastMarkId THEN
      RAISE EXCEPTION 'emaj_snap_log_group: mark id for "%" (% = %) is greater than mark id for "%" (% = %).', v_realFirstMark, v_firstMarkId, v_firstMarkTs, v_realLastMark, v_lastMarkId, v_lastMarkTs;
    END IF;
-- build the conditions on emaj_gid corresponding to this marks frame, used for the COPY statements dumping the tables
    v_conditions = 'TRUE';
    IF v_firstMark IS NOT NULL AND v_firstMark <> '' THEN
      v_conditions = v_conditions || ' AND emaj_gid > '|| v_firstEmajGid;
    END IF;
    IF v_lastMark IS NOT NULL AND v_lastMark <> '' THEN
      v_conditions = v_conditions || ' AND emaj_gid <= '|| v_lastEmajGid;
    END IF;
-- process all log tables of the emaj_relation table
    FOR r_tblsq IN
        SELECT rel_priority, rel_schema, rel_tblseq, rel_kind, rel_log_schema, rel_log_table FROM emaj.emaj_relation
          WHERE rel_group = v_groupName ORDER BY rel_priority, rel_schema, rel_tblseq
        LOOP
      IF r_tblsq.rel_kind = 'r' THEN
-- process tables
--   build names
        v_fileName = v_dir || '/' || r_tblsq.rel_schema || '_' || r_tblsq.rel_tblseq || '_log.snap';
        v_logTableName = quote_ident(r_tblsq.rel_log_schema) || '.' || quote_ident(r_tblsq.rel_log_table);
--   prepare the execute the COPY statement
        v_stmt= 'COPY (SELECT * FROM ' || v_logTableName || ' WHERE ' || v_conditions
             || ' ORDER BY emaj_gid ASC) TO ' || quote_literal(v_fileName)
             || ' ' || coalesce (v_copyOptions, '');
        EXECUTE v_stmt;
      END IF;
-- for sequences, just adjust the counter
      v_nbTb = v_nbTb + 1;
    END LOOP;
-- generate the file for sequences state at start mark
    v_fileName = v_dir || '/' || v_groupName || '_sequences_at_' || v_realFirstMark;
-- execute the COPY statement
    v_stmt= 'COPY (SELECT emaj_sequence.*' ||
            ' FROM emaj.emaj_sequence, emaj.emaj_relation' ||
            ' WHERE sequ_time_id = ' || quote_literal(v_firstMarkTsId) || ' AND ' ||
            ' rel_kind = ''S'' AND rel_group = ' || quote_literal(v_groupName) || ' AND' ||
            ' sequ_schema = rel_schema AND sequ_name = rel_tblseq' ||
            ' ORDER BY sequ_schema, sequ_name) TO ' || quote_literal(v_fileName) || ' ' ||
            coalesce (v_copyOptions, '');
    EXECUTE v_stmt;
-- generate the full file name for sequences state at end mark
    IF v_lastMark IS NOT NULL AND v_lastMark <> '' THEN
      v_fileName = v_dir || '/' || v_groupName || '_sequences_at_' || v_realLastMark;
    ELSE
      v_fileName = v_dir || '/' || v_groupName || '_sequences_at_' || to_char(v_lastMarkTs,'HH24.MI.SS.MS');
    END IF;
-- execute the COPY statement
    v_stmt= 'COPY (SELECT emaj_sequence.*' ||
            ' FROM emaj.emaj_sequence, emaj.emaj_relation' ||
            ' WHERE sequ_time_id = ' || quote_literal(v_lastMarkTsId) || ' AND ' ||
            ' rel_kind = ''S'' AND rel_group = ' || quote_literal(v_groupName) || ' AND' ||
            ' sequ_schema = rel_schema AND sequ_name = rel_tblseq' ||
            ' ORDER BY sequ_schema, sequ_name) TO ' || quote_literal(v_fileName) || ' ' ||
            coalesce (v_copyOptions, '');
    EXECUTE v_stmt;
    IF v_lastMark IS NULL OR v_lastMark = '' THEN
-- no last mark has been supplied, suppress the just created mark
      PERFORM emaj._delete_intermediate_mark_group(v_groupName, v_realLastMark, mark_id, mark_time_id)
        FROM emaj.emaj_mark WHERE mark_group = v_groupName AND mark_name = v_realLastMark;
    END IF;
-- create the _INFO file to keep general information about the snap operation
    EXECUTE 'COPY (SELECT ' ||
            quote_literal('E-Maj log tables snap of group ' || v_groupName ||
            ' between marks ' || v_realFirstMark || ' and ' ||
            coalesce(v_realLastMark,'current state') || ' at ' || statement_timestamp()) ||
            ') TO ' || quote_literal(v_dir || '/_INFO') || ' ' || coalesce (v_copyOptions, '');
-- insert end in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('SNAP_LOG_GROUP', 'END', v_groupName, v_nbTb || ' tables/sequences processed');
    RETURN v_nbTb;
  END;
$emaj_snap_log_group$;
COMMENT ON FUNCTION emaj.emaj_snap_log_group(TEXT,TEXT,TEXT,TEXT,TEXT) IS
$$Snaps all application tables and sequences of an E-Maj group into a given directory.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_gen_sql_group(v_groupName TEXT, v_firstMark TEXT, v_lastMark TEXT, v_location TEXT, v_tblseqs TEXT[] DEFAULT NULL)
RETURNS BIGINT LANGUAGE plpgsql SECURITY DEFINER SET standard_conforming_strings = ON AS
$emaj_gen_sql_group$
-- This function generates a SQL script representing all updates performed on a tables group between 2 marks
-- or beetween a mark and the current situation. The result is stored into an external file.
-- It call the _gen_sql_groups() function to effetively process the request
-- Input: - tables group
--        - start mark, NULL representing the first mark
--        - end mark, NULL representing the current situation, and 'EMAJ_LAST_MARK' the last set mark for the group
--        - absolute pathname describing the file that will hold the result
--        - array of schema qualified table and sequence names to only process those tables and sequences (NULL by default)
-- Output: number of generated SQL statements (non counting comments and transaction management)
  DECLARE
    v_cumNbSQL               BIGINT;
  BEGIN
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('GEN_SQL_GROUP', 'BEGIN', v_groupName,
       CASE WHEN v_firstMark IS NULL OR v_firstMark = '' THEN 'From initial mark' ELSE 'From mark ' || v_firstMark END ||
       CASE WHEN v_lastMark IS NULL OR v_lastMark = '' THEN ' to current situation' ELSE ' to mark ' || v_lastMark END ||
       ' towards ' || v_location ||
       CASE WHEN v_tblseqs IS NOT NULL THEN ' with tables/sequences filtering' ELSE '' END );
-- call the _gen_sql_groups() function that effectively processes the request
    SELECT emaj._gen_sql_groups(CASE WHEN v_groupName IS NOT NULL THEN array[v_groupName] ELSE NULL END, v_firstMark, v_lastMark, v_location, v_tblseqs)
      INTO v_cumNbSQL;
-- insert end in the history and return
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('GEN_SQL_GROUP', 'END', v_groupName, v_cumNbSQL || ' generated statements');
    RETURN v_cumNbSQL;
  END;
$emaj_gen_sql_group$;
COMMENT ON FUNCTION emaj.emaj_gen_sql_group(TEXT,TEXT,TEXT,TEXT,TEXT[]) IS
$$Generates a sql script corresponding to all updates performed on a tables group between two marks and stores it into a given file.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_gen_sql_groups(v_groupNames TEXT[], v_firstMark TEXT, v_lastMark TEXT, v_location TEXT, v_tblseqs TEXT[] DEFAULT NULL)
RETURNS BIGINT LANGUAGE plpgsql SECURITY DEFINER SET standard_conforming_strings = ON AS
$emaj_gen_sql_groups$
-- This function generates a SQL script representing all updates performed on a set of tables groups between 2 marks
-- or beetween a mark and the current situation. The result is stored into an external file.
-- It call the _gen_sql_groups() function to effetively process the request
-- Input: - tables groups array
--        - start mark, NULL representing the first mark
--        - end mark, NULL representing the current situation, and 'EMAJ_LAST_MARK' the last set mark for the group
--        - absolute pathname describing the file that will hold the result
--        - array of schema qualified table and sequence names to only process those tables and sequences (NULL by default)
-- Output: number of generated SQL statements (non counting comments and transaction management)
  DECLARE
    v_cumNbSQL               BIGINT;
  BEGIN
-- insert begin in the history
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('GEN_SQL_GROUPS', 'BEGIN', array_to_string(v_groupNames,','),
       CASE WHEN v_firstMark IS NULL OR v_firstMark = '' THEN 'From initial mark' ELSE 'From mark ' || v_firstMark END ||
       CASE WHEN v_lastMark IS NULL OR v_lastMark = '' THEN ' to current situation' ELSE ' to mark ' || v_lastMark END ||
       ' towards ' || v_location ||
       CASE WHEN v_tblseqs IS NOT NULL THEN ' with tables/sequences filtering' ELSE '' END );
-- call the _gen_sql_groups() function that effectively processes the request
    SELECT emaj._gen_sql_groups(v_groupNames, v_firstMark, v_lastMark, v_location, v_tblseqs) INTO v_cumNbSQL;
-- insert end in the history and return
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
      VALUES ('GEN_SQL_GROUPS', 'END', array_to_string(v_groupNames,','), v_cumNbSQL || ' generated statements');
    RETURN v_cumNbSQL;
  END;
$emaj_gen_sql_groups$;
COMMENT ON FUNCTION emaj.emaj_gen_sql_groups(TEXT[],TEXT,TEXT,TEXT,TEXT[]) IS
$$Generates a sql script corresponding to all updates performed on a set of tables groups between two marks and stores it into a given file.$$;

CREATE OR REPLACE FUNCTION emaj._gen_sql_groups(v_groupNames TEXT[], v_firstMark TEXT, v_lastMark TEXT, v_location TEXT, v_tblseqs TEXT[])
RETURNS BIGINT LANGUAGE plpgsql SECURITY DEFINER SET standard_conforming_strings = ON AS
$_gen_sql_groups$
-- This function generates a SQL script representing all updates performed on a tables groups array between 2 marks
-- or beetween a mark and the current situation. The result is stored into an external file.
-- The function can process groups that are in LOGGING state or not.
-- The sql statements are placed between a BEGIN TRANSACTION and a COMMIT statements.
-- The output file can be reused as input file to a psql command to replay the updates scenario. Just '\\'
-- character strings (double antislash), if any, must be replaced by '\' (single antislash) before feeding
-- the psql command.
-- Input: - tables groups array
--        - start mark, NULL representing the first mark
--        - end mark, NULL representing the current situation, and 'EMAJ_LAST_MARK' the last set mark for the group
--        - absolute pathname describing the file that will hold the result
--        - optional array of schema qualified table and sequence names to only process those tables and sequences
-- Output: number of generated SQL statements (non counting comments and transaction management)
  DECLARE
    v_aGroupName             TEXT;
    v_tblList                TEXT;
    v_cpt                    INT;
    v_firstMarkCopy          TEXT = v_firstMark;
    v_realFirstMark          TEXT;
    v_realLastMark           TEXT;
    v_firstMarkTimeId        BIGINT;
    v_firstEmajGid           BIGINT;
    v_lastEmajGid            BIGINT;
    v_firstMarkTs            TIMESTAMPTZ;
    v_lastMarkTs             TIMESTAMPTZ;
    v_lastMarkTimeId         BIGINT;
    v_tblseqErr              TEXT;
    v_nbSQL                  BIGINT;
    v_nbSeq                  INT;
    v_cumNbSQL               BIGINT = 0;
    v_fullSeqName            TEXT;
    v_endComment             TEXT;
    v_conditions             TEXT;
    v_rqSeq                  TEXT;
    r_tblsq                  RECORD;
    r_rel                    emaj.emaj_relation%ROWTYPE;
  BEGIN
-- check group names array and stop the processing if it is null
    v_groupNames = emaj._check_names_array(v_groupNames,'group');
    IF v_groupNames IS NULL THEN
      RETURN 0;
    END IF;
-- if table/sequence names are supplied, check them
    IF v_tblseqs IS NOT NULL THEN
      IF v_tblseqs = array[''] THEN
        RAISE EXCEPTION '_gen_sql_groups: filtered table/sequence names array cannot be empty.';
      END IF;
      v_tblseqs = emaj._check_names_array(v_tblseqs,'table/sequence');
    END IF;
-- check that each group ...
    FOREACH v_aGroupName IN ARRAY v_groupNames LOOP
-- ...is recorded into the emaj_group table
      PERFORM 0 FROM emaj.emaj_group WHERE group_name = v_aGroupName;
      IF NOT FOUND THEN
        RAISE EXCEPTION '_gen_sql_groups: group "%" has not been created.', v_aGroupName;
      END IF;
-- ... has no tables without pkey
      SELECT string_agg(rel_schema || '.' || rel_tblseq,',') INTO v_tblList
        FROM pg_catalog.pg_class, pg_catalog.pg_namespace, emaj.emaj_relation
        WHERE relnamespace = pg_namespace.oid
          AND nspname = rel_schema AND relname = rel_tblseq
          AND rel_group = v_aGroupName AND rel_kind = 'r'
          AND relhaspkey = false;
      IF v_tblList IS NOT NULL THEN
        RAISE EXCEPTION '_gen_sql_groups: Tables group "%" contains tables without pkey (%).', v_aGroupName, v_tblList;
      END IF;
-- If the first mark supplied is NULL or empty, get the first mark for the current processed group
--   (in fact the first one) and override the supplied first mark
      IF v_firstMarkCopy IS NULL OR v_firstMarkCopy = '' THEN
        SELECT mark_name INTO v_firstMarkCopy
          FROM emaj.emaj_mark WHERE mark_group = v_aGroupName ORDER BY mark_id LIMIT 1;
        IF NOT FOUND THEN
           RAISE EXCEPTION '_gen_sql_groups: No initial mark can be found for group "%".', v_aGroupName;
        END IF;
      END IF;
-- ... owns the requested first mark
      SELECT emaj._get_mark_name(v_aGroupName,v_firstMarkCopy) INTO v_realFirstMark;
      IF v_realFirstMark IS NULL THEN
        RAISE EXCEPTION '_gen_sql_groups: Begin mark "%" does not exist for group "%".', v_firstMarkCopy, v_aGroupName;
      END IF;
-- ... and owns the requested last mark, if supplied
      IF v_lastMark IS NOT NULL AND v_lastMark <> '' THEN
        SELECT emaj._get_mark_name(v_aGroupName,v_lastMark) INTO v_realLastMark;
        IF v_realLastMark IS NULL THEN
          RAISE EXCEPTION '_gen_sql_groups: End mark "%" does not exist for group "%".', v_lastMark, v_aGroupName;
        END IF;
      END IF;
    END LOOP;
-- check that the first mark timestamp is the same for all groups of the array
    SELECT count(DISTINCT emaj._get_mark_time_id(group_name,v_firstMarkCopy)) INTO v_cpt FROM emaj.emaj_group
      WHERE group_name = ANY (v_groupNames);
    IF v_cpt > 1 THEN
      RAISE EXCEPTION '_gen_sql_groups: Begin mark "%" does not represent the same point in time for all groups.', v_firstMarkCopy;
    END IF;
-- check that the last mark timestamp, if supplied, is the same for all groups of the array
    IF v_lastMark IS NOT NULL AND v_lastMark <> '' THEN
      SELECT count(DISTINCT emaj._get_mark_time_id(group_name,v_lastMark)) INTO v_cpt FROM emaj.emaj_group
        WHERE group_name = ANY (v_groupNames);
      IF v_cpt > 1 THEN
        RAISE EXCEPTION '_gen_sql_groups: End mark "%" does not represent the same point in time for all groups.', v_lastMark;
      END IF;
    END IF;
-- retrieve the name, the global sequence value and the timestamp of the supplied first mark for the 1st group
--   (the global sequence value and the timestamp are the same for all groups of the array)
    SELECT mark_time_id, time_last_emaj_gid, time_clock_timestamp INTO v_firstMarkTimeId, v_firstEmajGid, v_firstMarkTs
      FROM emaj.emaj_mark, emaj.emaj_time_stamp
      WHERE mark_time_id = time_id AND mark_group = v_groupNames[1] AND mark_name = v_realFirstMark;
-- if last mark is NULL or empty, there is no timestamp to register
    IF v_lastMark IS NULL OR v_lastMark = '' THEN
      v_lastEmajGid = NULL;
      v_lastMarkTs = NULL;
      v_lastMarkTimeId = NULL;
    ELSE
-- else, retrieve the name, timestamp and last global sequence id of the supplied end mark for the 1st group
      SELECT mark_time_id, time_last_emaj_gid, time_clock_timestamp INTO v_lastMarkTimeId, v_lastEmajGid, v_lastMarkTs
        FROM emaj.emaj_mark, emaj.emaj_time_stamp
        WHERE mark_time_id = time_id AND mark_group = v_groupNames[1] AND mark_name = v_realLastMark;
    END IF;
-- check that the first_mark < end_mark
    IF v_lastMarkTimeId IS NOT NULL AND v_firstMarkTimeId > v_lastMarkTimeId THEN
      RAISE EXCEPTION '_gen_sql_groups: time stamp for "%" (%) is greater than for "%" (%).', v_firstMarkCopy, v_firstMarkTs, v_lastMark, v_lastMarkTs;
    END IF;
-- check the array of tables and sequences to filter, if supplied.
-- each table/sequence of the filter must be known in emaj_relation and be owned by one of the supplied table groups
    IF v_tblseqs IS NOT NULL THEN
      SELECT string_agg(t,', ') INTO v_tblseqErr FROM (
        SELECT t FROM unnest(v_tblseqs) AS t
          EXCEPT
        SELECT rel_schema || '.' || rel_tblseq FROM emaj.emaj_relation
          WHERE rel_group = ANY (v_groupNames)
        ) AS t2;
      IF v_tblseqErr IS NOT NULL THEN
        RAISE EXCEPTION '_gen_sql_groups: some tables and/or sequences (%) do not belong to any of the selected tables groups.', v_tblseqErr;
      END IF;
    END IF;
-- test the supplied output file name by inserting a temporary line (trap NULL or bad file name)
    BEGIN
      EXECUTE 'COPY (SELECT ''-- _gen_sql_groups() function in progress - started at '
                     || statement_timestamp() || ''') TO ' || quote_literal(v_location);
    EXCEPTION
      WHEN OTHERS THEN
        RAISE EXCEPTION '_gen_sql_groups: file "%" cannot be used as script output file.', v_location;
    END;
-- create temporary table
    CREATE TEMP TABLE emaj_temp_script (
      scr_emaj_gid           BIGINT,              -- the emaj_gid of the corresponding log row,
                                                  --   0 for initial technical statements,
                                                  --   NULL for final technical statements
      scr_subid              INT,                 -- used to distinguish several generated sql per log row
      scr_emaj_txid          BIGINT,              -- for future use, to insert commit statement at each txid change
      scr_sql                TEXT                 -- the generated sql text
    );
-- for each application table referenced in the emaj_relation table, build SQL statements and process the related log table
-- build the restriction conditions on emaj_gid, depending on supplied mark range (the same for all tables)
    v_conditions = 'o.emaj_gid > ' || v_firstEmajGid;
    IF v_lastMarkTimeId IS NOT NULL THEN
      v_conditions = v_conditions || ' AND o.emaj_gid <= ' || v_lastEmajGid;
    END IF;
    FOR r_rel IN
        SELECT * FROM emaj.emaj_relation
          WHERE rel_group = ANY (v_groupNames) AND rel_kind = 'r'                        -- tables of the groups
            AND (v_tblseqs IS NULL OR rel_schema || '.' || rel_tblseq = ANY (v_tblseqs)) -- filtered or not by the user
                                                                               -- only tables having updates to process
            AND emaj._log_stat_tbl(emaj_relation, v_firstMarkTimeId, v_lastMarkTimeId) > 0
          ORDER BY rel_priority, rel_schema, rel_tblseq
        LOOP
-- process the application table, by calling the _gen_sql_tbl function
      SELECT emaj._gen_sql_tbl(r_rel, v_conditions) INTO v_nbSQL;
      v_cumNbSQL = v_cumNbSQL + v_nbSQL;
    END LOOP;
-- process sequences
    v_nbSeq = 0;
    FOR r_tblsq IN
        SELECT rel_priority, rel_schema, rel_tblseq FROM emaj.emaj_relation
          WHERE rel_group = ANY (v_groupNames) AND rel_kind = 'S'                        -- sequences of the groups
            AND (v_tblseqs IS NULL OR rel_schema || '.' || rel_tblseq = ANY (v_tblseqs)) -- filtered or not by the user
          ORDER BY rel_priority DESC, rel_schema DESC, rel_tblseq DESC
        LOOP
      v_fullSeqName = quote_ident(r_tblsq.rel_schema) || '.' || quote_ident(r_tblsq.rel_tblseq);
      IF v_lastMarkTimeId IS NULL THEN
-- no supplied last mark, so get current sequence characteritics
        EXECUTE 'SELECT ''ALTER SEQUENCE ' || replace(v_fullSeqName,'''','''''')
                || ''' || '' RESTART '' || CASE WHEN is_called THEN last_value + increment_by ELSE last_value END || '' START '' || start_value || '' INCREMENT '' || increment_by  || '' MAXVALUE '' || max_value  || '' MINVALUE '' || min_value || '' CACHE '' || cache_value || CASE WHEN NOT is_cycled THEN '' NO'' ELSE '''' END || '' CYCLE;'' '
               || 'FROM ' || v_fullSeqName INTO v_rqSeq;
      ELSE
-- a last mark is supplied, so get sequence characteristics from emaj_sequence table
        EXECUTE 'SELECT ''ALTER SEQUENCE ' || replace(v_fullSeqName,'''','''''')
               || ''' || '' RESTART '' || CASE WHEN sequ_is_called THEN sequ_last_val + sequ_increment ELSE sequ_last_val END || '' START '' || sequ_start_val || '' INCREMENT '' || sequ_increment  || '' MAXVALUE '' || sequ_max_val  || '' MINVALUE '' || sequ_min_val || '' CACHE '' || sequ_cache_val || CASE WHEN NOT sequ_is_cycled THEN '' NO'' ELSE '''' END || '' CYCLE;'' '
               || 'FROM emaj.emaj_sequence '
               || 'WHERE sequ_schema = ' || quote_literal(r_tblsq.rel_schema)
               || '  AND sequ_name = ' || quote_literal(r_tblsq.rel_tblseq)
               || '  AND sequ_time_id = ' || v_lastMarkTimeId INTO v_rqSeq;
      END IF;
-- insert into temp table
      v_nbSeq = v_nbSeq + 1;
      EXECUTE 'INSERT INTO emaj_temp_script '
           || 'SELECT NULL, -1 * ' || v_nbSeq || ', txid_current(), ' || quote_literal(v_rqSeq);
    END LOOP;
-- add initial comments
    IF v_lastMarkTimeId IS NOT NULL THEN
      v_endComment = ' and mark ' || v_realLastMark;
    ELSE
      v_endComment = ' and the current situation';
    END IF;
    INSERT INTO emaj_temp_script SELECT 0, 1, 0, '-- SQL script generated by E-Maj at ' || statement_timestamp();
    INSERT INTO emaj_temp_script SELECT 0, 2, 0, '--    for tables group(s): ' || array_to_string(v_groupNames,',');
    INSERT INTO emaj_temp_script SELECT 0, 3, 0, '--    processing logs between mark ' || v_realFirstMark || v_endComment;
    IF v_tblseqs IS NOT NULL THEN
      INSERT INTO emaj_temp_script SELECT 0, 4, 0, '--    only for the following tables/sequences: ' || array_to_string(v_tblseqs,',');
    END IF;
-- encapsulate the sql statements inside a TRANSACTION
-- and manage the standard_conforming_strings option to properly handle special characters
    INSERT INTO emaj_temp_script SELECT 0, 10, 0, 'SET standard_conforming_strings = ON;';
    INSERT INTO emaj_temp_script SELECT 0, 11, 0, 'BEGIN TRANSACTION;';
    INSERT INTO emaj_temp_script SELECT NULL, 1, txid_current(), 'COMMIT;';
    INSERT INTO emaj_temp_script SELECT NULL, 2, txid_current(), 'RESET standard_conforming_strings;';
-- write the SQL script on the external file
    EXECUTE 'COPY (SELECT scr_sql FROM emaj_temp_script ORDER BY scr_emaj_gid NULLS LAST, scr_subid ) TO '
          || quote_literal(v_location);
-- drop temporary table
    DROP TABLE IF EXISTS emaj_temp_script;
-- return the number of sql verbs generated into the output file
    v_cumNbSQL = v_cumNbSQL + v_nbSeq;
    RETURN v_cumNbSQL;
  END;
$_gen_sql_groups$;

CREATE OR REPLACE FUNCTION emaj._verify_all_groups()
RETURNS SETOF TEXT LANGUAGE plpgsql AS
$_verify_all_groups$
-- The function verifies the consistency of all E-Maj groups.
-- It returns a set of warning messages for discovered discrepancies. If no error is detected, no row is returned.
  DECLARE
  BEGIN
-- check the postgres version at groups creation time is compatible (i.e. >= 9.1)
    RETURN QUERY
      SELECT 'The group "' || group_name || '" has been created with a non compatible postgresql version (' ||
               group_pg_version || '). It must be dropped and recreated.' AS msg
        FROM emaj.emaj_group
        WHERE cast(to_number(substring(group_pg_version FROM E'^(\\d+)'),'99') * 100 +
                   to_number(substring(group_pg_version FROM E'^\\d+\\.(\\d+)'),'99') AS INTEGER) < 901
        ORDER BY msg;
-- check all application schemas referenced in the emaj_relation table still exist
    RETURN QUERY
      SELECT 'The application schema "' || rel_schema || '" does not exist any more.' AS msg
        FROM (
          SELECT DISTINCT rel_schema FROM emaj.emaj_relation
            EXCEPT
          SELECT nspname FROM pg_catalog.pg_namespace
             ) AS t
        ORDER BY msg;
-- check all application relations referenced in the emaj_relation table still exist
    RETURN QUERY
      SELECT 'In group "' || r.rel_group || '", the ' ||
               CASE WHEN t.rel_kind = 'r' THEN 'table "' ELSE 'sequence "' END ||
               t.rel_schema || '"."' || t.rel_tblseq || '" does not exist any more.' AS msg
        FROM (                                        -- all expected application relations
          SELECT rel_schema, rel_tblseq, rel_kind FROM emaj.emaj_relation
            EXCEPT                                    -- minus relations known by postgres
          SELECT nspname, relname, relkind FROM pg_catalog.pg_class, pg_catalog.pg_namespace
            WHERE relnamespace = pg_namespace.oid AND relkind IN ('r','S')
             ) AS t, emaj.emaj_relation r             -- join with emaj_relation to get the group name
        WHERE t.rel_schema = r.rel_schema AND t.rel_tblseq = r.rel_tblseq
        ORDER BY t.rel_schema, t.rel_tblseq, 1;
-- check the log table for all tables referenced in the emaj_relation table still exist
    RETURN QUERY
      SELECT 'In group "' || rel_group || '", the log table "' ||
               rel_log_schema || '"."' || rel_log_table || '" is not found.' AS msg
        FROM emaj.emaj_relation
        WHERE rel_kind = 'r'
          AND NOT EXISTS
              (SELECT NULL FROM pg_catalog.pg_namespace, pg_catalog.pg_class
                 WHERE nspname = rel_log_schema AND relname = rel_log_table
                   AND relnamespace = pg_namespace.oid)
        ORDER BY rel_schema, rel_tblseq, 1;
-- check the log function for each table referenced in the emaj_relation table still exist
    RETURN QUERY
      SELECT 'In group "' || rel_group || '", the log function "' || rel_log_schema || '"."' || rel_log_function || '" is not found.' AS msg
        FROM emaj.emaj_relation
        WHERE rel_kind = 'r'
          AND NOT EXISTS
              (SELECT NULL FROM pg_catalog.pg_proc, pg_catalog.pg_namespace
                 WHERE nspname = rel_log_schema AND proname = rel_log_function
                   AND pronamespace = pg_namespace.oid)
        ORDER BY rel_schema, rel_tblseq, 1;
-- check log and truncate triggers for all tables referenced in the emaj_relation table still exist
--   start with log triggers
    RETURN QUERY
      SELECT 'In group "' || rel_group || '", the log trigger "emaj_log_trg" on table "' ||
               rel_schema || '"."' || rel_tblseq || '" is not found.' AS msg
        FROM emaj.emaj_relation
        WHERE rel_kind = 'r'
          AND NOT EXISTS
              (SELECT NULL FROM pg_catalog.pg_trigger, pg_catalog.pg_namespace, pg_catalog.pg_class
                 WHERE nspname = rel_schema AND relname = rel_tblseq AND tgname = 'emaj_log_trg'
                   AND tgrelid = pg_class.oid AND relnamespace = pg_namespace.oid)
                       -- do not issue a row if the application table does not exist,
                       -- this case has been already detected
          AND EXISTS
              (SELECT NULL FROM pg_catalog.pg_class, pg_catalog.pg_namespace
                 WHERE nspname = rel_schema AND relname = rel_tblseq AND relnamespace = pg_namespace.oid)
        ORDER BY rel_schema, rel_tblseq, 1;
--   then truncate triggers
    RETURN QUERY
      SELECT 'In group "' || rel_group || '", the truncate trigger "emaj_trunc_trg" on table "' ||
             rel_schema || '"."' || rel_tblseq || '" is not found.' AS msg
        FROM emaj.emaj_relation
        WHERE rel_kind = 'r'
          AND NOT EXISTS
              (SELECT NULL FROM pg_catalog.pg_trigger, pg_catalog.pg_namespace, pg_catalog.pg_class
                 WHERE nspname = rel_schema AND relname = rel_tblseq AND tgname = 'emaj_trunc_trg'
                   AND tgrelid = pg_class.oid AND relnamespace = pg_namespace.oid)
                       -- do not issue a row if the application table does not exist,
                       -- this case has been already detected
          AND EXISTS
              (SELECT NULL FROM pg_catalog.pg_class, pg_catalog.pg_namespace
                 WHERE nspname = rel_schema AND relname = rel_tblseq AND relnamespace = pg_namespace.oid)
        ORDER BY rel_schema, rel_tblseq, 1;
-- check all log tables have a structure consistent with the application tables they reference
--      (same columns and same formats). It only returns one row per faulting table.
    RETURN QUERY
      SELECT msg FROM (
        WITH cte_app_tables_columns AS (                -- application table's columns
            SELECT rel_group, rel_schema, rel_tblseq, rel_log_schema, rel_log_table, attname, atttypid, attlen, atttypmod
              FROM emaj.emaj_relation, pg_catalog.pg_attribute, pg_catalog.pg_class, pg_catalog.pg_namespace
              WHERE relnamespace = pg_namespace.oid AND nspname = rel_schema AND relname = rel_tblseq
                AND attrelid = pg_class.oid AND attnum > 0 AND attisdropped = false
                AND rel_kind = 'r'),
             cte_log_tables_columns AS (                -- log table's columns
            SELECT rel_group, rel_schema, rel_tblseq, rel_log_schema, rel_log_table, attname, atttypid, attlen, atttypmod
              FROM emaj.emaj_relation, pg_catalog.pg_attribute, pg_catalog.pg_class, pg_catalog.pg_namespace
              WHERE relnamespace = pg_namespace.oid AND nspname = rel_log_schema
                AND relname = rel_log_table
                AND attrelid = pg_class.oid AND attnum > 0 AND attisdropped = false AND attname NOT LIKE 'emaj%'
                AND rel_kind = 'r')
        SELECT DISTINCT rel_schema, rel_tblseq,
               'In group "' || rel_group || '", the structure of the application table "' ||
                 rel_schema || '"."' || rel_tblseq || '" is not coherent with its log table ("' ||
               rel_log_schema || '"."' || rel_log_table || '").' AS msg
          FROM (
            (                                           -- application table's columns
            SELECT rel_group, rel_schema, rel_tblseq, rel_log_schema, rel_log_table, attname, atttypid, attlen, atttypmod
              FROM cte_app_tables_columns
            EXCEPT                                      -- minus log table's columns
            SELECT rel_group, rel_schema, rel_tblseq, rel_log_schema, rel_log_table, attname, atttypid, attlen, atttypmod
              FROM cte_log_tables_columns
            )
            UNION
            (                                           -- log table's columns
            SELECT rel_group, rel_schema, rel_tblseq, rel_log_schema, rel_log_table, attname, atttypid, attlen, atttypmod
              FROM cte_log_tables_columns
            EXCEPT                                      --  minus application table's columns
            SELECT rel_group, rel_schema, rel_tblseq, rel_log_schema, rel_log_table, attname, atttypid, attlen, atttypmod
              FROM cte_app_tables_columns
            )) AS t
                           -- do not issue a row if the log or application table does not exist,
                           -- these cases have been already detected
        WHERE (rel_log_schema, rel_log_table) IN
              (SELECT nspname, relname FROM pg_catalog.pg_class, pg_catalog.pg_namespace
                 WHERE relnamespace = pg_namespace.oid)
          AND (rel_schema, rel_tblseq) IN
              (SELECT nspname, relname FROM pg_catalog.pg_class, pg_catalog.pg_namespace
                 WHERE relnamespace = pg_namespace.oid)
        ORDER BY 1,2,3
        ) AS t;
    RETURN;
  END;
$_verify_all_groups$;

CREATE OR REPLACE FUNCTION emaj._verify_all_schemas()
RETURNS SETOF TEXT LANGUAGE plpgsql AS
$_verify_all_schemas$
-- The function verifies that all E-Maj schemas only contains E-Maj objects.
-- It returns a set of warning messages for discovered discrepancies. If no error is detected, no row is returned.
  DECLARE
    v_emajSchema             TEXT = 'emaj';
  BEGIN
-- verify that the expected E-Maj schemas still exist
    RETURN QUERY
      SELECT DISTINCT 'The E-Maj schema "' || rel_log_schema || '" does not exist any more.' AS msg
        FROM emaj.emaj_relation
        WHERE rel_log_schema IS NOT NULL
          AND NOT EXISTS (SELECT NULL FROM pg_catalog.pg_namespace WHERE nspname = rel_log_schema)
        ORDER BY msg;
-- detect all objects that are not directly linked to a known table groups in all E-Maj schemas
-- scan pg_class, pg_proc, pg_type, pg_conversion, pg_operator, pg_opclass
    RETURN QUERY
      SELECT msg FROM (
        WITH cte_logschemas AS (SELECT DISTINCT rel_log_schema FROM emaj.emaj_relation)
-- look for unexpected tables
        SELECT nspname, 1, 'In schema "' || nspname ||
               '", the table "' || nspname || '"."' || relname || '" is not linked to any created tables group.' AS msg
           FROM pg_catalog.pg_class, pg_catalog.pg_namespace
           WHERE relnamespace = pg_namespace.oid AND relkind = 'r'
             AND (nspname <> v_emajSchema OR relname NOT LIKE E'emaj\\_%')    -- exclude emaj internal tables
             AND NOT EXISTS                                                   -- exclude emaj log tables
                (SELECT NULL FROM emaj.emaj_relation WHERE rel_log_schema = nspname AND rel_log_table = relname)
             AND nspname IN (SELECT rel_log_schema FROM cte_logschemas)
        UNION ALL
-- look for unexpected sequences
        SELECT nspname, 2, 'In schema "' || nspname ||
               '", the sequence "' || nspname || '"."' || relname || '" is not linked to any created tables group.' AS msg
           FROM pg_catalog.pg_class, pg_catalog.pg_namespace
           WHERE relnamespace = pg_namespace.oid AND relkind = 'S'
             AND (nspname <> v_emajSchema OR relname NOT LIKE E'emaj\\_%')    -- exclude emaj internal sequences
             AND NOT EXISTS                                                   -- exclude emaj log table sequences
                (SELECT NULL FROM emaj.emaj_relation WHERE rel_log_schema = nspname AND rel_log_sequence = relname)
             AND nspname IN (SELECT rel_log_schema FROM cte_logschemas)
        UNION ALL
-- look for unexpected functions
        SELECT nspname, 3, 'In schema "' || nspname ||
               '", the function "' || nspname || '"."' || proname  || '" is not linked to any created tables group.' AS msg
           FROM pg_catalog.pg_proc, pg_catalog.pg_namespace
           WHERE pronamespace = pg_namespace.oid
             AND (nspname <> v_emajSchema OR (proname NOT LIKE E'emaj\\_%' AND proname NOT LIKE E'\\_%'))
                                                                              -- exclude emaj internal functions
             AND NOT EXISTS (                                                 -- exclude emaj log functions
               SELECT NULL FROM emaj.emaj_relation WHERE rel_log_schema = nspname AND rel_log_function = proname)
             AND nspname IN (SELECT rel_log_schema FROM cte_logschemas)
        UNION ALL
-- look for unexpected composite types
        SELECT nspname, 4, 'In schema "' || nspname ||
               '", the type "' || nspname || '"."' || relname || '" is not an E-Maj component.' AS msg
           FROM pg_catalog.pg_class, pg_catalog.pg_namespace
           WHERE relnamespace = pg_namespace.oid AND relkind = 'c'
             AND (nspname <> v_emajSchema OR (relname NOT LIKE E'emaj\\_%' AND relname NOT LIKE E'\\_%'))
                                                                              -- exclude emaj internal types
             AND nspname IN (SELECT rel_log_schema FROM cte_logschemas)
        UNION ALL
-- look for unexpected views
        SELECT nspname, 5, 'In schema "' || nspname ||
               '", the view "' || nspname || '"."' || relname || '" is not an E-Maj component.' AS msg
           FROM pg_catalog.pg_class, pg_catalog.pg_namespace
           WHERE relnamespace = pg_namespace.oid  AND relkind = 'v'
             AND (nspname <> v_emajSchema OR relname NOT LIKE E'emaj\\_%')    -- exclude emaj internal views
             AND nspname IN (SELECT rel_log_schema FROM cte_logschemas)
        UNION ALL
-- look for unexpected foreign tables
        SELECT nspname, 6, 'In schema "' || nspname ||
               '", the foreign table "' || nspname || '"."' || relname || '" is not an E-Maj component.' AS msg
           FROM pg_catalog.pg_class, pg_catalog.pg_namespace
           WHERE relnamespace = pg_namespace.oid  AND relkind = 'f'
             AND nspname IN (SELECT rel_log_schema FROM cte_logschemas)
        UNION ALL
-- look for unexpected domains
        SELECT nspname, 7, 'In schema "' || nspname ||
               '", the domain "' || nspname || '"."' || typname || '" is not an E-Maj component.' AS msg
           FROM pg_catalog.pg_type, pg_catalog.pg_namespace
           WHERE typnamespace = pg_namespace.oid AND typisdefined and typtype = 'd'
             AND nspname IN (SELECT rel_log_schema FROM cte_logschemas)
        UNION ALL
-- look for unexpected conversions
        SELECT nspname, 8, 'In schema "' || nspname ||
               '", the conversion "' || nspname || '"."' || conname || '" is not an E-Maj component.' AS msg
           FROM pg_catalog.pg_conversion, pg_catalog.pg_namespace
           WHERE connamespace = pg_namespace.oid
             AND nspname IN (SELECT rel_log_schema FROM cte_logschemas)
        UNION ALL
-- look for unexpected operators
        SELECT nspname, 9, 'In schema "' || nspname ||
               '", the operator "' || nspname || '"."' || oprname || '" is not an E-Maj component.' AS msg
           FROM pg_catalog.pg_operator, pg_catalog.pg_namespace
           WHERE oprnamespace = pg_namespace.oid
             AND nspname IN (SELECT rel_log_schema FROM cte_logschemas)
        UNION ALL
-- look for unexpected operator classes
        SELECT nspname, 10, 'In schema "' || nspname ||
               '", the operator class "' || nspname || '"."' || opcname || '" is not an E-Maj component.' AS msg
           FROM pg_catalog.pg_opclass, pg_catalog.pg_namespace
           WHERE opcnamespace = pg_namespace.oid
             AND nspname IN (SELECT rel_log_schema FROM cte_logschemas)
        ORDER BY 1, 2, 3
      ) AS t;
    RETURN;
  END;
$_verify_all_schemas$;

CREATE OR REPLACE FUNCTION emaj.emaj_verify_all()
RETURNS SETOF TEXT LANGUAGE plpgsql AS
$emaj_verify_all$
-- The function verifies the consistency between all emaj objects present inside emaj schema and
-- emaj objects related to tables and sequences referenced in emaj_relation table.
-- It returns a set of warning messages for discovered discrepancies. If no error is detected, a single row is returned.
  DECLARE
    v_errorFound             BOOLEAN = FALSE;
    v_nbMissingEventTrigger  INT;
    r_object                 RECORD;
  BEGIN
-- Global checks
-- detect if the current postgres version is at least 9.1
    IF emaj._pg_version_num() < 90100 THEN
      RETURN NEXT 'The current postgres version (' || version() || ') is not compatible with E-Maj.';
      v_errorFound = TRUE;
    END IF;
    IF emaj._pg_version_num() >= 90300 THEN
-- With postgres 9.3+, report a warning if some E-Maj event triggers are missing
      SELECT (CASE WHEN emaj._pg_version_num() >= 90500 THEN 3 WHEN emaj._pg_version_num() >= 90300 THEN 2 END) - count(*)
        INTO v_nbMissingEventTrigger FROM pg_catalog.pg_event_trigger
        WHERE evtname IN ('emaj_protection_trg','emaj_sql_drop_trg','emaj_table_rewrite_trg');
      IF v_nbMissingEventTrigger > 0 THEN
        RETURN NEXT 'Warning: some E-Maj event triggers are missing. Your database administrator may (re)create them using the emaj_upgrade_after_postgres_upgrade.sql script.';
      END IF;
-- With postgres 9.3+, report a warning if some E-Maj event triggers exist but are not enabled
      PERFORM 1 FROM pg_catalog.pg_event_trigger WHERE evtname LIKE 'emaj%' AND evtenabled = 'D';
      IF FOUND THEN
        RETURN NEXT 'Warning: some E-Maj event triggers exist but are disabled. You may enable them using the emaj_enable_protection_by_event_triggers() function.';
      END IF;
    END IF;
-- check all E-Maj primary and secondary schemas
    FOR r_object IN
      SELECT msg FROM emaj._verify_all_schemas() msg
    LOOP
      RETURN NEXT r_object.msg;
      v_errorFound = TRUE;
    END LOOP;
-- check all groups components
    FOR r_object IN
      SELECT msg FROM emaj._verify_all_groups() msg
    LOOP
      RETURN NEXT r_object.msg;
      v_errorFound = TRUE;
    END LOOP;
-- final message if no error has been yet detected
    IF NOT v_errorFound THEN
      RETURN NEXT 'No error detected';
    END IF;
    RETURN;
  END;
$emaj_verify_all$;
COMMENT ON FUNCTION emaj.emaj_verify_all() IS
$$Verifies the consistency between existing E-Maj and application objects.$$;

--<end_functions>                                pattern used by the tool that extracts and insert the functions definition
------------------------------------------
--                                      --
-- event triggers and related functions --
--                                      --
------------------------------------------
--
-- Event triggers creation depends on postgres version:
-- - sql_drop event trigger needs postgres 9.3+
-- - table_rewrite trigger needs postgres 9.5+
-- If E-Maj has been installed with older postgres versions, and this version has then been upgraded, the
-- set_event_triggers_protection.sql script can be used to add the missing components.

DO
$do$
BEGIN

-- beginning of 9.3+ specific code
IF emaj._pg_version_num() >= 90300 THEN
-- sql_drop event trigger are only possible with postgres 9.3+

CREATE OR REPLACE FUNCTION public._emaj_protection_event_trigger_fnct()
 RETURNS EVENT_TRIGGER LANGUAGE plpgsql AS
$_emaj_protection_event_trigger_fnct$
-- This function is called by the emaj_protection_trg event trigger
-- The function only blocks any attempt to drop the emaj schema or the emaj extension
-- It is located into the public schema to be able to detect the emaj schema removal attempt
-- It is also unlinked from the emaj extension to be able to detest the emaj extension removal attempt
-- Another pair of function and event trigger handles all other drop attempts
  DECLARE
    r_dropped                RECORD;
  BEGIN
-- scan all dropped objects
    FOR r_dropped IN
      SELECT object_type, object_name FROM pg_event_trigger_dropped_objects()
    LOOP
      IF r_dropped.object_type = 'schema' AND r_dropped.object_name = 'emaj' THEN
-- detecting an attempt to drop the emaj object
        RAISE EXCEPTION 'E-Maj event trigger: attempting to drop the schema "emaj". Please use the emaj_uninstall.sql script if you really want to remove all E-Maj components.';
      END IF;
      IF r_dropped.object_type = 'extension' AND r_dropped.object_name = 'emaj' THEN
-- detecting an attempt to drop the emaj extension
        RAISE EXCEPTION 'E-Maj event trigger: attempting to drop the emaj extension. Please use the emaj_uninstall.sql script if you really want to remove all E-Maj components.';
      END IF;
    END LOOP;
  END;
$_emaj_protection_event_trigger_fnct$;
COMMENT ON FUNCTION public._emaj_protection_event_trigger_fnct() IS
$$E-Maj extension: support of the emaj_protection_trg event trigger.$$;

-- all commands involving an event trigger is submitted by an EXECUTE instruction
-- this is needed for compatibility with pre 9.3 postgres version that do not know event triggers
EXECUTE '
DROP EVENT TRIGGER IF EXISTS emaj_protection_trg;
CREATE EVENT TRIGGER emaj_protection_trg
  ON sql_drop
  WHEN TAG IN (''DROP EXTENSION'',''DROP SCHEMA'')
  EXECUTE PROCEDURE public._emaj_protection_event_trigger_fnct();
';
EXECUTE '
COMMENT ON EVENT TRIGGER emaj_protection_trg IS
$$Blocks the removal of the emaj extension or schema.$$;
';

-- remove both event trigger components from the extension, so that they can fire the "DROP EXTENSION emaj"
ALTER EXTENSION emaj DROP FUNCTION public._emaj_protection_event_trigger_fnct();
EXECUTE '
ALTER EXTENSION emaj DROP EVENT TRIGGER emaj_protection_trg;
';

CREATE OR REPLACE FUNCTION emaj._event_trigger_sql_drop_fnct()
 RETURNS EVENT_TRIGGER LANGUAGE plpgsql AS
$_event_trigger_sql_drop_fnct$
-- This function is called by the emaj_sql_drop_trg event trigger
-- The function blocks any ddl operation that leads to a drop of
--   - an application table or a sequence registered into an active (not stopped) E-Maj group, or a schema containing such tables/sequence
--   - an E-Maj schema, a log table, a log sequence, a log function or a log trigger
-- The drop of emaj schema or extension is managed by another event trigger
  DECLARE
    v_groupName              TEXT;
    r_dropped                RECORD;
  BEGIN
-- scan all dropped objects
    FOR r_dropped IN
      SELECT * FROM pg_event_trigger_dropped_objects()
-- TODO: when postgres 9.4 will not be supported any more, replace the statement by:
--      SELECT object_type, schema_name, object_name, object_identity, original FROM pg_event_trigger_dropped_objects()
-- (the 'original' column is not known in pg9.4- versions)
    LOOP
      CASE
        WHEN r_dropped.object_type = 'schema' THEN
-- the object is a schema
--   look at the emaj_relation table to verify that the schema being dropped does not belong to any active (not stopped) group
          SELECT string_agg(DISTINCT rel_group, ', ') INTO v_groupName FROM emaj.emaj_relation, emaj.emaj_group
            WHERE rel_schema = r_dropped.object_name
              AND group_name = rel_group AND group_is_logging;
          IF v_groupName IS NOT NULL THEN
            RAISE EXCEPTION 'E-Maj event trigger: attempting to drop the application schema "%". But it belongs to the active tables groups "%".', r_dropped.object_name, v_groupName;
          END IF;
--   look at the emaj_relation table to verify that the schema being dropped is not an E-Maj schema containing log tables
          PERFORM 1 FROM emaj.emaj_relation
            WHERE rel_log_schema = r_dropped.object_name;
          IF FOUND THEN
            RAISE EXCEPTION 'E-Maj event trigger: attempting to drop the schema "%". But dropping an E-Maj schema is not allowed.', r_dropped.object_name;
          END IF;
        WHEN r_dropped.object_type = 'table' THEN
-- the object is a table
--   look at the emaj_relation table to verify that the table being dropped does not belong to any active (not stopped) group
          SELECT rel_group INTO v_groupName FROM emaj.emaj_relation, emaj.emaj_group
            WHERE rel_schema = r_dropped.schema_name AND rel_tblseq = r_dropped.object_name
              AND group_name = rel_group AND group_is_logging;
          IF FOUND THEN
            RAISE EXCEPTION 'E-Maj event trigger: attempting to drop the application table "%.%". But it belongs to the active tables group "%".', r_dropped.schema_name, r_dropped.object_name, v_groupName;
          END IF;
--   look at the emaj_relation table to verify that the table being dropped is not a log table
          PERFORM 1 FROM emaj.emaj_relation
            WHERE rel_log_schema = r_dropped.schema_name AND rel_log_table = r_dropped.object_name;
          IF FOUND THEN
            RAISE EXCEPTION 'E-Maj event trigger: attempting to drop the log table "%.%". But dropping an E-Maj log table is not allowed.',
                            r_dropped.schema_name, r_dropped.object_name;
          END IF;
        WHEN r_dropped.object_type = 'sequence' THEN
-- the object is a sequence
--   look at the emaj_relation table to verify that the sequence being dropped does not belong to any active (not stopped) group
          SELECT rel_group INTO v_groupName FROM emaj.emaj_relation, emaj.emaj_group
            WHERE rel_schema = r_dropped.schema_name AND rel_tblseq = r_dropped.object_name
              AND group_name = rel_group AND group_is_logging;
          IF FOUND THEN
            RAISE EXCEPTION 'E-Maj event trigger: attempting to drop the application sequence "%.%". But it belongs to the active tables group "%".', r_dropped.schema_name, r_dropped.object_name, v_groupName;
          END IF;
--   look at the emaj_relation table to verify that the sequence being dropped is not a log sequence
          PERFORM 1 FROM emaj.emaj_relation
            WHERE rel_log_schema = r_dropped.schema_name AND rel_log_sequence = r_dropped.object_name;
          IF FOUND THEN
            RAISE EXCEPTION 'E-Maj event trigger: attempting to drop the log sequence "%.%". But dropping an E-Maj sequence is not allowed.', r_dropped.schema_name, r_dropped.object_name;
          END IF;
        WHEN r_dropped.object_type = 'function' THEN
-- the object is a function
--   look at the emaj_relation table to verify that the function being dropped is not a log function
          PERFORM 1 FROM emaj.emaj_relation
            WHERE  r_dropped.object_identity = quote_ident(rel_log_schema) || '.' || quote_ident(rel_log_function) || '()';
          IF FOUND THEN
            RAISE EXCEPTION 'E-Maj event trigger: attempting to drop the log function "%". But dropping an E-Maj log function is not allowed.', r_dropped.object_identity;
          END IF;
        WHEN r_dropped.object_type = 'trigger' THEN
-- the object is a trigger
--   if postgres version is 9.5+ (to see the 'original' column of the pg_event_trigger_dropped_objects() function),
--   look at the trigger name pattern to identify emaj trigger
--   and do not raise an exception if the triggers drop is derived from a drop of a table or a function
          IF emaj._pg_version_num() >= 90500 THEN
            IF r_dropped.original AND
               (r_dropped.object_identity LIKE 'emaj_log_trg%' OR r_dropped.object_identity LIKE 'emaj_trunc_trg%') THEN
              RAISE EXCEPTION 'E-Maj event trigger: attempting to drop the "%" E-Maj trigger. But dropping an E-Maj trigger is not allowed.', r_dropped.object_identity;
            END IF;
          END IF;
        ELSE
          CONTINUE;
      END CASE;
    END LOOP;
  END;
$_event_trigger_sql_drop_fnct$;

COMMENT ON FUNCTION emaj._event_trigger_sql_drop_fnct() IS
$$E-Maj extension: support of the emaj_sql_drop_trg event trigger.$$;

EXECUTE '
DROP EVENT TRIGGER IF EXISTS emaj_sql_drop_trg;
CREATE EVENT TRIGGER emaj_sql_drop_trg
  ON sql_drop
  WHEN TAG IN (''DROP FUNCTION'',''DROP SCHEMA'',''DROP SEQUENCE'',''DROP TABLE'',''DROP TRIGGER'')
  EXECUTE PROCEDURE emaj._event_trigger_sql_drop_fnct();
';
EXECUTE '
COMMENT ON EVENT TRIGGER emaj_sql_drop_trg IS
$$Controls the removal of E-Maj components.$$;
';

-- end of 9.3+ specific code
END IF;

-- beginning of 9.5+ specific code
IF emaj._pg_version_num() >= 90500 THEN
-- table_rewrite event trigger are only possible with postgres 9.5+

CREATE OR REPLACE FUNCTION emaj._emaj_event_trigger_table_rewrite_fnct()
 RETURNS EVENT_TRIGGER LANGUAGE plpgsql AS
$_emaj_event_trigger_table_rewrite_fnct$
-- This function is called by the emaj_table_rewrite_trg event trigger
-- The function blocks any ddl operation that leads to a table rewrite for:
--   - an application table registered into an active (not stopped) E-Maj group
--   - an E-Maj log table
  DECLARE
    v_tableSchema            TEXT;
    v_tableName              TEXT;
    v_groupName              TEXT;
  BEGIN
-- get the schema and table names of the altered table
    SELECT nspname, relname INTO v_tableSchema, v_tableName FROM pg_catalog.pg_class, pg_catalog.pg_namespace
      WHERE relnamespace = pg_namespace.oid AND pg_class.oid = pg_event_trigger_table_rewrite_oid();
-- look at the emaj_relation table to verify that the table being rewritten does not belong to any active (not stopped) group
    SELECT rel_group INTO v_groupName FROM emaj.emaj_relation, emaj.emaj_group
      WHERE rel_schema = v_tableSchema AND rel_tblseq = v_tableName
              AND group_name = rel_group AND group_is_logging;
    IF FOUND THEN
-- the table is an application table that belongs to a group, so raise an exception
      RAISE EXCEPTION 'E-Maj event trigger: attempting to change the application table "%.%" structure. But the table belongs to the active tables group "%".',
                      v_tableSchema, v_tableName , v_groupName;
    END IF;
-- look at the emaj_relation table to verify that the table being rewritten is not a known log table
    SELECT rel_group INTO v_groupName FROM emaj.emaj_relation
      WHERE rel_log_schema = v_tableSchema AND rel_log_table = v_tableName;
    IF FOUND THEN
-- the table is an E-Maj log table, so raise an exception
      RAISE EXCEPTION 'E-Maj event trigger: attempting to change the log table "%.%" structure. But the table belongs to the tables group "%".',
                      v_tableSchema, v_tableName , v_groupName;
    END IF;
  END;
$_emaj_event_trigger_table_rewrite_fnct$;

COMMENT ON FUNCTION emaj._emaj_event_trigger_table_rewrite_fnct() IS
$$E-Maj extension: support of the emaj_table_rewrite_trg event trigger.$$;

EXECUTE '
DROP EVENT TRIGGER IF EXISTS emaj_table_rewrite_trg;
CREATE EVENT TRIGGER emaj_table_rewrite_trg
  ON table_rewrite
  EXECUTE PROCEDURE emaj._emaj_event_trigger_table_rewrite_fnct();
';
EXECUTE '
COMMENT ON EVENT TRIGGER emaj_table_rewrite_trg IS
$$Controls some changes in E-Maj tables structure.$$;
';

-- end of 9.5+ specific code
END IF;
END $do$;

CREATE OR REPLACE FUNCTION emaj.emaj_disable_protection_by_event_triggers()
 RETURNS INT LANGUAGE plpgsql AS
$emaj_disable_protection_by_event_triggers$
-- This function disables all known E-Maj event triggers that are in enabled state.
-- It may be used by an emaj_adm role.
-- Output: number of effectively disabled event triggers
  DECLARE
    v_event_trigger_array TEXT[];
  BEGIN
-- call the _disable_event_triggers() function and get the disabled event trigger names array
    SELECT emaj._disable_event_triggers() INTO v_event_trigger_array;
-- insert a row into the emaj_hist table
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_wording)
      VALUES ('DISABLE_PROTECTION', 'EVENT TRIGGERS DISABLED',
              CASE WHEN v_event_trigger_array <> ARRAY[]::TEXT[] THEN array_to_string(v_event_trigger_array, ', ') ELSE '<none>' END);
-- return the number of disabled event triggers
    RETURN coalesce(array_length(v_event_trigger_array,1),0);
  END;
$emaj_disable_protection_by_event_triggers$;

COMMENT ON FUNCTION emaj.emaj_disable_protection_by_event_triggers() IS
$$Disables the protection of E-Maj components by event triggers.$$;

CREATE OR REPLACE FUNCTION emaj.emaj_enable_protection_by_event_triggers()
 RETURNS INT LANGUAGE plpgsql AS
$emaj_enable_protection_by_event_triggers$
-- This function enables all known E-Maj event triggers that are in disabled state.
-- It may be used by an emaj_adm role.
-- Output: number of effectively enabled event triggers
  DECLARE
    v_event_trigger_array    TEXT[];
  BEGIN
    IF emaj._pg_version_num() >= 90300 THEN
-- build the event trigger names array from the pg_event_trigger table
-- (pg_event_trigger table doesn't exists in 9.2- postgres versions)
      SELECT coalesce(array_agg(evtname),ARRAY[]::TEXT[]) INTO v_event_trigger_array
        FROM pg_catalog.pg_event_trigger WHERE evtname LIKE 'emaj%' AND evtenabled = 'D';
-- call the _enable_event_triggers() function
      PERFORM emaj._enable_event_triggers(v_event_trigger_array);
    END IF;
-- insert a row into the emaj_hist table
    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_wording)
      VALUES ('ENABLE_PROTECTION', 'EVENT TRIGGERS ENABLED',
              CASE WHEN v_event_trigger_array <> ARRAY[]::TEXT[] THEN array_to_string(v_event_trigger_array, ', ') ELSE '<none>' END);
-- return the number of disabled event triggers
    RETURN coalesce(array_length(v_event_trigger_array,1),0);
  END;
$emaj_enable_protection_by_event_triggers$;

COMMENT ON FUNCTION emaj.emaj_enable_protection_by_event_triggers() IS
$$Enables the protection of E-Maj components by event triggers.$$;

CREATE OR REPLACE FUNCTION emaj._disable_event_triggers()
 RETURNS TEXT[] LANGUAGE plpgsql SECURITY DEFINER AS
$_disable_event_triggers$
-- This function disables all known E-Maj event triggers that are in enabled state.
-- The function is called by functions that alter or drop E-Maj components, such as emaj_drop_group().
-- It is also called by the user emaj_disable_event_triggers_protection() function.
-- Output: array of effectively disabled event trigger names. It can be reused as input when calling _enable_event_triggers()
  DECLARE
    v_event_trigger          TEXT;
    v_event_trigger_array    TEXT[] = ARRAY[]::TEXT[];
  BEGIN
    IF emaj._pg_version_num() >= 90300 THEN
-- build the event trigger names array from the pg_event_trigger table
-- (pg_event_trigger table doesn't exists in 9.2- postgres versions)
      SELECT coalesce(array_agg(evtname),ARRAY[]::TEXT[]) INTO v_event_trigger_array
        FROM pg_catalog.pg_event_trigger WHERE evtname LIKE 'emaj%' AND evtenabled <> 'D';
-- disable each event trigger
      FOREACH v_event_trigger IN ARRAY v_event_trigger_array
      LOOP
        EXECUTE 'ALTER EVENT TRIGGER ' || v_event_trigger || ' DISABLE';
      END LOOP;
    END IF;
    RETURN v_event_trigger_array;
  END;
$_disable_event_triggers$;

CREATE OR REPLACE FUNCTION emaj._enable_event_triggers(v_event_trigger_array TEXT[])
 RETURNS TEXT[] LANGUAGE plpgsql SECURITY DEFINER AS
$_enable_event_triggers$
-- This function enables all event triggers supplied as parameter
-- The function is called by functions that alter or drop E-Maj components, such as emaj_drop_group().
-- It is also called by the user emaj_enable_event_triggers_protection() function.
-- Input: array of event trigger names to enable
-- Output: same array
  DECLARE
    v_event_trigger          TEXT;
  BEGIN
    FOREACH v_event_trigger IN ARRAY v_event_trigger_array
    LOOP
      EXECUTE 'ALTER EVENT TRIGGER ' || v_event_trigger || ' ENABLE';
    END LOOP;
    RETURN v_event_trigger_array;
  END;
$_enable_event_triggers$;

------------------------------------
--                                --
-- emaj roles and rights          --
--                                --
------------------------------------
REVOKE ALL ON ALL FUNCTIONS IN SCHEMA emaj FROM PUBLIC;

GRANT ALL ON ALL TABLES IN SCHEMA emaj TO emaj_adm;
GRANT ALL ON ALL SEQUENCES IN SCHEMA emaj TO emaj_adm;
GRANT EXECUTE ON ALL FUNCTIONS IN SCHEMA emaj TO emaj_adm;

GRANT SELECT ON ALL TABLES IN SCHEMA emaj TO emaj_viewer;
GRANT SELECT ON ALL SEQUENCES IN SCHEMA emaj TO emaj_viewer;
REVOKE SELECT ON TABLE emaj.emaj_param FROM emaj_viewer;

GRANT EXECUTE ON FUNCTION emaj._log_stat_tbl(r_rel emaj.emaj_relation, v_firstMarkTimeId BIGINT, v_lastMarkTimeId BIGINT) TO emaj_viewer;
GRANT EXECUTE ON FUNCTION emaj.emaj_get_consolidable_rollbacks() TO emaj_viewer;

------------------------------------
--                                --
-- complete the upgrade           --
--                                --
------------------------------------

-- Set comments for all internal functions,
-- by directly inserting a row in the pg_description table for all emaj functions that do not have yet a recorded comment
INSERT INTO pg_catalog.pg_description (objoid, classoid, objsubid, description)
  SELECT pg_proc.oid, pg_class.oid, 0 , 'E-Maj internal function'
    FROM pg_catalog.pg_proc, pg_catalog.pg_class
    WHERE pg_class.relname = 'pg_proc'
      AND pg_proc.oid IN               -- list all emaj functions that do not have yet a comment in pg_description
       (SELECT pg_proc.oid
          FROM pg_catalog.pg_proc
               JOIN pg_catalog.pg_namespace ON (pronamespace=pg_namespace.oid)
               LEFT OUTER JOIN pg_catalog.pg_description ON (pg_description.objoid = pg_proc.oid
                                     AND classoid = (SELECT oid FROM pg_catalog.pg_class WHERE relname = 'pg_proc')
                                     AND objsubid = 0)
          WHERE nspname = 'emaj' AND (proname LIKE E'emaj\\_%' OR proname LIKE E'\\_%')
            AND pg_description.description IS NULL
       );

-- update the version id in the emaj_param table
UPDATE emaj.emaj_param SET param_value_text = '2.0.0' WHERE param_key = 'emaj_version';

-- insert the upgrade record in the operation history
INSERT INTO emaj.emaj_hist (hist_function, hist_object, hist_wording) VALUES ('EMAJ_INSTALL','E-Maj 2.0.0', 'Upgrade from 1.3.1 completed');

-- post installation checks
DO
$tmp$
  DECLARE
  BEGIN
-- check the max_prepared_transactions GUC value
    IF current_setting('max_prepared_transactions')::int <= 1 THEN
      RAISE WARNING 'E-Maj upgrade: as the max_prepared_transactions parameter value (%) on this cluster is too low, no parallel rollback is possible.', current_setting('max_prepared_transactions');
    END IF;
  END;
$tmp$;

RESET default_tablespace;
SET client_min_messages TO default;