/*------------------------------------------------------------------------- * * shared_library_init.c * Functionality related to the initialization of the Citus extension. * * Copyright (c) Citus Data, Inc. *------------------------------------------------------------------------- */ #include "postgres.h" #include #include #include /* necessary to get alloca on illumos */ #ifdef __sun #include #endif #include "fmgr.h" #include "miscadmin.h" #include "safe_lib.h" #include "citus_version.h" #include "commands/explain.h" #include "executor/executor.h" #include "distributed/backend_data.h" #include "distributed/citus_nodefuncs.h" #include "distributed/citus_safe_lib.h" #include "distributed/commands.h" #include "distributed/commands/multi_copy.h" #include "distributed/commands/utility_hook.h" #include "distributed/connection_management.h" #include "distributed/cte_inline.h" #include "distributed/distributed_deadlock_detection.h" #include "distributed/insert_select_executor.h" #include "distributed/intermediate_result_pruning.h" #include "distributed/local_executor.h" #include "distributed/locally_reserved_shared_connections.h" #include "distributed/maintenanced.h" #include "distributed/metadata_utility.h" #include "distributed/coordinator_protocol.h" #include "distributed/metadata_cache.h" #include "distributed/metadata_sync.h" #include "distributed/multi_physical_planner.h" #include "distributed/multi_executor.h" #include "distributed/multi_explain.h" #include "distributed/multi_join_order.h" #include "distributed/multi_logical_optimizer.h" #include "distributed/distributed_planner.h" #include "distributed/combine_query_planner.h" #include "distributed/multi_router_planner.h" #include "distributed/multi_server_executor.h" #include "distributed/pg_dist_partition.h" #include "distributed/placement_connection.h" #include "distributed/reference_table_utils.h" #include "distributed/relation_access_tracking.h" #include "distributed/run_from_same_connection.h" #include "distributed/shared_connection_stats.h" #include "distributed/query_pushdown_planning.h" #include "distributed/time_constants.h" #include "distributed/query_stats.h" #include "distributed/remote_commands.h" #include "distributed/shared_library_init.h" #include "distributed/statistics_collection.h" #include "distributed/subplan_execution.h" #include "distributed/transaction_management.h" #include "distributed/transaction_recovery.h" #include "distributed/worker_log_messages.h" #include "distributed/worker_manager.h" #include "distributed/worker_protocol.h" #include "distributed/worker_shard_visibility.h" #include "distributed/adaptive_executor.h" #include "port/atomics.h" #include "postmaster/postmaster.h" #include "storage/ipc.h" #include "optimizer/planner.h" #include "optimizer/paths.h" #include "tcop/tcopprot.h" #include "utils/guc.h" #include "utils/guc_tables.h" #include "utils/varlena.h" /* marks shared object as one loadable by the postgres version compiled against */ PG_MODULE_MAGIC; #define DUMMY_REAL_TIME_EXECUTOR_ENUM_VALUE 9999999 static char *CitusVersion = CITUS_VERSION; void _PG_init(void); static void DoInitialCleanup(void); static void ResizeStackToMaximumDepth(void); static void multi_log_hook(ErrorData *edata); static void RegisterConnectionCleanup(void); static void CitusCleanupConnectionsAtExit(int code, Datum arg); static void CreateRequiredDirectories(void); static void RegisterCitusConfigVariables(void); static bool ErrorIfNotASuitableDeadlockFactor(double *newval, void **extra, GucSource source); static bool WarnIfDeprecatedExecutorUsed(int *newval, void **extra, GucSource source); static bool NoticeIfSubqueryPushdownEnabled(bool *newval, void **extra, GucSource source); static bool NodeConninfoGucCheckHook(char **newval, void **extra, GucSource source); static void NodeConninfoGucAssignHook(const char *newval, void *extra); static const char * MaxSharedPoolSizeGucShowHook(void); static bool StatisticsCollectionGucCheckHook(bool *newval, void **extra, GucSource source); /* static variable to hold value of deprecated GUC variable */ static bool DeprecatedBool = false; static int DeprecatedInt = 0; /* *INDENT-OFF* */ /* GUC enum definitions */ static const struct config_enum_entry propagate_set_commands_options[] = { {"none", PROPSETCMD_NONE, false}, {"local", PROPSETCMD_LOCAL, false}, {NULL, 0, false} }; static const struct config_enum_entry task_assignment_policy_options[] = { { "greedy", TASK_ASSIGNMENT_GREEDY, false }, { "first-replica", TASK_ASSIGNMENT_FIRST_REPLICA, false }, { "round-robin", TASK_ASSIGNMENT_ROUND_ROBIN, false }, { NULL, 0, false } }; static const struct config_enum_entry replication_model_options[] = { { "statement", REPLICATION_MODEL_COORDINATOR, false }, { "streaming", REPLICATION_MODEL_STREAMING, false }, { NULL, 0, false } }; static const struct config_enum_entry task_executor_type_options[] = { { "adaptive", MULTI_EXECUTOR_ADAPTIVE, false }, { "real-time", DUMMY_REAL_TIME_EXECUTOR_ENUM_VALUE, false }, /* keep it for backward comp. */ { "task-tracker", MULTI_EXECUTOR_ADAPTIVE, false }, { NULL, 0, false } }; static const struct config_enum_entry shard_placement_policy_options[] = { { "local-node-first", SHARD_PLACEMENT_LOCAL_NODE_FIRST, false }, { "round-robin", SHARD_PLACEMENT_ROUND_ROBIN, false }, { "random", SHARD_PLACEMENT_RANDOM, false }, { NULL, 0, false } }; static const struct config_enum_entry use_secondary_nodes_options[] = { { "never", USE_SECONDARY_NODES_NEVER, false }, { "always", USE_SECONDARY_NODES_ALWAYS, false }, { NULL, 0, false } }; static const struct config_enum_entry coordinator_aggregation_options[] = { { "disabled", COORDINATOR_AGGREGATION_DISABLED, false }, { "row-gather", COORDINATOR_AGGREGATION_ROW_GATHER, false }, { NULL, 0, false } }; static const struct config_enum_entry shard_commit_protocol_options[] = { { "1pc", COMMIT_PROTOCOL_1PC, false }, { "2pc", COMMIT_PROTOCOL_2PC, false }, { NULL, 0, false } }; static const struct config_enum_entry log_level_options[] = { { "off", CITUS_LOG_LEVEL_OFF, false }, { "debug5", DEBUG5, false}, { "debug4", DEBUG4, false}, { "debug3", DEBUG3, false}, { "debug2", DEBUG2, false}, { "debug1", DEBUG1, false}, { "debug", DEBUG2, true}, { "log", LOG, false}, { "info", INFO, true}, { "notice", NOTICE, false}, { "warning", WARNING, false}, { "error", ERROR, false}, { NULL, 0, false} }; static const struct config_enum_entry multi_shard_modify_connection_options[] = { { "parallel", PARALLEL_CONNECTION, false }, { "sequential", SEQUENTIAL_CONNECTION, false }, { NULL, 0, false } }; static const struct config_enum_entry explain_analyze_sort_method_options[] = { { "execution-time", EXPLAIN_ANALYZE_SORT_BY_TIME, false }, { "taskId", EXPLAIN_ANALYZE_SORT_BY_TASK_ID, false }, { NULL, 0, false } }; /* *INDENT-ON* */ /* shared library initialization function */ void _PG_init(void) { if (!process_shared_preload_libraries_in_progress) { ereport(ERROR, (errmsg("Citus can only be loaded via shared_preload_libraries"), errhint("Add citus to shared_preload_libraries configuration " "variable in postgresql.conf in master and workers. Note " "that citus should be at the beginning of " "shared_preload_libraries."))); } /* * Register contstraint_handler hooks of safestringlib first. This way * loading the extension will error out if one of these constraints are hit * during load. */ set_str_constraint_handler_s(ereport_constraint_handler); set_mem_constraint_handler_s(ereport_constraint_handler); /* * Perform checks before registering any hooks, to avoid erroring out in a * partial state. * * In many cases (e.g. planner and utility hook, to run inside * pg_stat_statements et. al.) we have to be loaded before other hooks * (thus as the innermost/last running hook) to be able to do our * duties. For simplicity insist that all hooks are previously unused. */ if (planner_hook != NULL || ProcessUtility_hook != NULL || ExecutorStart_hook != NULL || ExecutorRun_hook != NULL || ExplainOneQuery_hook != NULL) { ereport(ERROR, (errmsg("Citus has to be loaded first"), errhint("Place citus at the beginning of " "shared_preload_libraries."))); } ResizeStackToMaximumDepth(); /* * Extend the database directory structure before continuing with * initialization - one of the later steps might require them to exist. * If in a sub-process (windows / EXEC_BACKEND) this already has been * done. */ if (!IsUnderPostmaster) { CreateRequiredDirectories(); } InitConnParams(); /* * Register Citus configuration variables. Do so before intercepting * hooks or calling initialization functions, in case we want to do the * latter in a configuration dependent manner. */ RegisterCitusConfigVariables(); /* make our additional node types known */ RegisterNodes(); /* make our custom scan nodes known */ RegisterCitusCustomScanMethods(); /* intercept planner */ planner_hook = distributed_planner; /* register utility hook */ ProcessUtility_hook = multi_ProcessUtility; /* register for planner hook */ set_rel_pathlist_hook = multi_relation_restriction_hook; set_join_pathlist_hook = multi_join_restriction_hook; ExecutorStart_hook = CitusExecutorStart; ExecutorRun_hook = CitusExecutorRun; ExplainOneQuery_hook = CitusExplainOneQuery; /* register hook for error messages */ emit_log_hook = multi_log_hook; InitializeMaintenanceDaemon(); /* initialize coordinated transaction management */ InitializeTransactionManagement(); InitializeBackendManagement(); InitializeConnectionManagement(); InitPlacementConnectionManagement(); InitializeCitusQueryStats(); InitializeSharedConnectionStats(); InitializeLocallyReservedSharedConnections(); /* enable modification of pg_catalog tables during pg_upgrade */ if (IsBinaryUpgrade) { SetConfigOption("allow_system_table_mods", "true", PGC_POSTMASTER, PGC_S_OVERRIDE); } /* * In postmasters execution of _PG_init, IsUnderPostmaster will be false and * we want to do the cleanup at that time only, otherwise there is a chance that * there will be parallel queries and we might do a cleanup for things that are * already in use. This is only needed in Windows. */ if (!IsUnderPostmaster) { DoInitialCleanup(); } } /* * DoInitialCleanup does cleanup at start time. * Currently it: * - Removes repartition directories ( in case there are any leftovers) */ static void DoInitialCleanup(void) { RepartitionCleanupJobDirectories(); } /* * Stack size increase during high memory load may cause unexpected crashes. * With this alloca call, we are increasing stack size explicitly, so that if * it is not possible to increase stack size, we will get an OOM error instead * of a crash. * * This function is called on backend startup. The allocated memory will * automatically be released at the end of the function's scope. However, we'd * have already expanded the stack and it wouldn't shrink back. So, in a sense, * per backend we're securing max_stack_depth kB's of memory on the stack upfront. * * Not all the backends require max_stack_depth kB's on the stack, so we might end * up with unnecessary allocations. However, the default value is 2MB, which seems * an acceptable trade-off. Also, allocating memory upfront may perform better * under some circumstances. */ static void ResizeStackToMaximumDepth(void) { #ifndef WIN32 long max_stack_depth_bytes = max_stack_depth * 1024L; /* * Explanation of IGNORE-BANNED: * alloca is safe to use here since we limit the allocated size. We cannot * use malloc as a replacement, since we actually want to grow the stack * here. */ volatile char *stack_resizer = alloca(max_stack_depth_bytes); /* IGNORE-BANNED */ /* * Different architectures might have different directions while * growing the stack. So, touch both ends. */ stack_resizer[0] = 0; stack_resizer[max_stack_depth_bytes - 1] = 0; /* * Passing the address to external function also prevents the function * from being optimized away, and the debug elog can also help with * diagnosis if needed. */ elog(DEBUG5, "entry stack is at %p, increased to %p, the top and bottom values of " "the stack is %d and %d", &stack_resizer[0], &stack_resizer[max_stack_depth_bytes - 1], stack_resizer[max_stack_depth_bytes - 1], stack_resizer[0]); #endif } /* * multi_log_hook intercepts postgres log commands. We use this to override * postgres error messages when they're not specific enough for the users. */ static void multi_log_hook(ErrorData *edata) { /* * Show the user a meaningful error message when a backend is cancelled * by the distributed deadlock detection. Also reset the state for this, * since the next cancelation of the backend might have another reason. */ bool clearState = true; if (edata->elevel == ERROR && edata->sqlerrcode == ERRCODE_QUERY_CANCELED && MyBackendGotCancelledDueToDeadlock(clearState)) { edata->sqlerrcode = ERRCODE_T_R_DEADLOCK_DETECTED; edata->message = "canceling the transaction since it was " "involved in a distributed deadlock"; } } /* * StartupCitusBackend initializes per-backend infrastructure, and is called * the first time citus is used in a database. * * NB: All code here has to be able to cope with this routine being called * multiple times in the same backend. This will e.g. happen when the * extension is created or upgraded. */ void StartupCitusBackend(void) { InitializeMaintenanceDaemonBackend(); InitializeBackendData(); RegisterConnectionCleanup(); } /* * RegisterConnectionCleanup cleans up any resources left at the end of the * session. We prefer to cleanup before shared memory exit to make sure that * this session properly releases anything hold in the shared memory. */ static void RegisterConnectionCleanup(void) { static bool registeredCleanup = false; if (registeredCleanup == false) { before_shmem_exit(CitusCleanupConnectionsAtExit, 0); registeredCleanup = true; } } /* * CitusCleanupConnectionsAtExit is called before_shmem_exit() of the * backend for the purposes of any clean-up needed. */ static void CitusCleanupConnectionsAtExit(int code, Datum arg) { /* properly close all the cached connections */ ShutdownAllConnections(); /* * Make sure that we give the shared connections back to the shared * pool if any. This operation is a no-op if the reserved connections * are already given away. */ DeallocateReservedConnections(); } /* * CreateRequiredDirectories - Create directories required for Citus to * function. * * These used to be created by initdb, but that's not possible anymore. */ static void CreateRequiredDirectories(void) { const char *subdirs[] = { "pg_foreign_file", "pg_foreign_file/cached", "base/" PG_JOB_CACHE_DIR }; for (int dirNo = 0; dirNo < lengthof(subdirs); dirNo++) { int ret = mkdir(subdirs[dirNo], S_IRWXU); if (ret != 0 && errno != EEXIST) { ereport(ERROR, (errcode_for_file_access(), errmsg("could not create directory \"%s\": %m", subdirs[dirNo]))); } } } /* Register Citus configuration variables. */ static void RegisterCitusConfigVariables(void) { DefineCustomIntVariable( "citus.node_connection_timeout", gettext_noop("Sets the maximum duration to connect to worker nodes."), NULL, &NodeConnectionTimeout, 30 * MS_PER_SECOND, 10 * MS, MS_PER_HOUR, PGC_USERSET, GUC_UNIT_MS | GUC_STANDARD, NULL, NULL, NULL); DefineCustomIntVariable( "citus.sslmode", gettext_noop("This variable has been deprecated. Use the citus.node_conninfo " "GUC instead."), NULL, &DeprecatedInt, 0, 0, 32, PGC_POSTMASTER, GUC_SUPERUSER_ONLY | GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.binary_master_copy_format", gettext_noop("This GUC variable has been deprecated."), NULL, &DeprecatedBool, false, PGC_USERSET, GUC_STANDARD | GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.binary_worker_copy_format", gettext_noop("Use the binary worker copy format."), gettext_noop("When enabled, data is copied from workers to workers " "in PostgreSQL's binary serialization format when " "joining large tables."), &BinaryWorkerCopyFormat, false, PGC_SIGHUP, GUC_STANDARD, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.expire_cached_shards", gettext_noop("This GUC variable has been deprecated."), NULL, &DeprecatedBool, false, PGC_SIGHUP, GUC_STANDARD | GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.enable_local_execution", gettext_noop("Enables queries on shards that are local to the current node " "to be planned and executed locally."), NULL, &EnableLocalExecution, true, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.enable_single_hash_repartition_joins", gettext_noop("Enables single hash repartitioning between hash " "distributed tables"), NULL, &EnableSingleHashRepartitioning, false, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.enable_repartitioned_insert_select", gettext_noop("Enables repartitioned INSERT/SELECTs"), NULL, &EnableRepartitionedInsertSelect, true, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.enable_fast_path_router_planner", gettext_noop("Enables fast path router planner"), NULL, &EnableFastPathRouterPlanner, true, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.enable_binary_protocol", gettext_noop( "Enables communication between nodes using binary protocol when possible"), NULL, &EnableBinaryProtocol, false, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.override_table_visibility", gettext_noop("Enables replacing occurencens of pg_catalog.pg_table_visible() " "with pg_catalog.citus_table_visible()"), gettext_noop("When enabled, shards on the Citus MX worker (data) nodes would be " "filtered out by many psql commands to provide better user " "experience."), &OverrideTableVisibility, true, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.enforce_foreign_key_restrictions", gettext_noop("Enforce restrictions while querying distributed/reference " "tables with foreign keys"), gettext_noop("When enabled, cascading modifications from reference tables " "to distributed tables are traced and acted accordingly " "to avoid creating distributed deadlocks and ensure correctness."), &EnforceForeignKeyRestrictions, true, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.subquery_pushdown", gettext_noop("Usage of this GUC is highly discouraged, please read the long " "description"), gettext_noop("When enabled, the planner skips many correctness checks " "for subqueries and pushes down the queries to shards as-is. " "It means that the queries are likely to return wrong results " "unless the user is absolutely sure that pushing down the " "subquery is safe. This GUC is maintained only for backward " "compatibility, no new users are supposed to use it. The planner" "is capable of pushing down as much computation as possible to the " "shards depending on the query."), &SubqueryPushdown, false, PGC_USERSET, GUC_NO_SHOW_ALL, NoticeIfSubqueryPushdownEnabled, NULL, NULL); DefineCustomBoolVariable( "citus.log_multi_join_order", gettext_noop("Logs the distributed join order to the server log."), gettext_noop("We use this private configuration entry as a debugging aid. " "If enabled, we print the distributed join order."), &LogMultiJoinOrder, false, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.log_remote_commands", gettext_noop("Log queries sent to other nodes in the server log"), NULL, &LogRemoteCommands, false, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.log_local_commands", gettext_noop("Log queries that are executed locally, can be overriden by " "citus.log_remote_commands"), NULL, &LogLocalCommands, false, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.log_intermediate_results", gettext_noop("Log intermediate results sent to other nodes"), NULL, &LogIntermediateResults, false, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.log_distributed_deadlock_detection", gettext_noop("Log distributed deadlock detection related processing in " "the server log"), NULL, &LogDistributedDeadlockDetection, false, PGC_SIGHUP, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomEnumVariable( "citus.worker_min_messages", gettext_noop("Log messages from workers only if their log level is at or above " "the configured level"), NULL, &WorkerMinMessages, NOTICE, log_level_options, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.explain_distributed_queries", gettext_noop("Enables Explain for distributed queries."), gettext_noop("When enabled, the Explain command shows remote and local " "plans when used with a distributed query. It is enabled " "by default, but can be disabled for regression tests."), &ExplainDistributedQueries, true, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.explain_all_tasks", gettext_noop("Enables showing output for all tasks in Explain."), gettext_noop("The Explain command for distributed queries shows " "the remote plan for a single task by default. When " "this configuration entry is enabled, the plan for " "all tasks is shown, but the Explain takes longer."), &ExplainAllTasks, false, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.all_modifications_commutative", gettext_noop("Bypasses commutativity checks when enabled"), NULL, &AllModificationsCommutative, false, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomRealVariable( "citus.distributed_deadlock_detection_factor", gettext_noop("Sets the time to wait before checking for distributed " "deadlocks. Postgres' deadlock_timeout setting is " "multiplied with the value. If the value is set to" "1000, distributed deadlock detection is disabled."), NULL, &DistributedDeadlockDetectionTimeoutFactor, 2.0, -1.0, 1000.0, PGC_SIGHUP, GUC_STANDARD, ErrorIfNotASuitableDeadlockFactor, NULL, NULL); DefineCustomIntVariable( "citus.recover_2pc_interval", gettext_noop("Sets the time to wait between recovering 2PCs."), gettext_noop("2PC transaction recovery needs to run every so often " "to clean up records in pg_dist_transaction and " "potentially roll failed 2PCs forward. This setting " "determines how often recovery should run, " "use -1 to disable."), &Recover2PCInterval, 60 * MS_PER_SECOND, -1, 7 * MS_PER_DAY, PGC_SIGHUP, GUC_UNIT_MS | GUC_STANDARD, NULL, NULL, NULL); DefineCustomIntVariable( "citus.metadata_sync_interval", gettext_noop("Sets the time to wait between metadata syncs."), gettext_noop("metadata sync needs to run every so often " "to synchronize metadata to metadata nodes " "that are out of sync."), &MetadataSyncInterval, 60 * MS_PER_SECOND, 1, 7 * MS_PER_DAY, PGC_SIGHUP, GUC_UNIT_MS | GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomIntVariable( "citus.metadata_sync_retry_interval", gettext_noop("Sets the interval to retry failed metadata syncs."), gettext_noop("metadata sync needs to run every so often " "to synchronize metadata to metadata nodes " "that are out of sync."), &MetadataSyncRetryInterval, 5 * MS_PER_SECOND, 1, 7 * MS_PER_DAY, PGC_SIGHUP, GUC_UNIT_MS | GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.select_opens_transaction_block", gettext_noop("Open transaction blocks for SELECT commands"), gettext_noop("When enabled, Citus will always send a BEGIN to workers when " "running a distributed SELECT in a transaction block (the " "default). When disabled, Citus will only send BEGIN before " "the first write or other operation that requires a distributed " "transaction, meaning the SELECT on the worker commits " "immediately, releasing any locks and apply any changes made " "through function calls even if the distributed transaction " "aborts."), &SelectOpensTransactionBlock, true, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.function_opens_transaction_block", gettext_noop("Open transaction blocks for function calls"), gettext_noop("When enabled, Citus will always send a BEGIN to workers when " "running distributed queres in a function. When disabled, the " "queries may be committed immediately after the statemnent " "completes. Disabling this flag is dangerous, it is only provided " "for backwards compatibility with pre-8.2 behaviour."), &FunctionOpensTransactionBlock, true, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.force_max_query_parallelization", gettext_noop("Open as many connections as possible to maximize query " "parallelization"), gettext_noop("When enabled, Citus will force the executor to use " "as many connections as possible while executing a " "parallel distributed query. If not enabled, the executor" "might choose to use less connections to optimize overall " "query execution throughput. Internally, setting this true " "will end up with using one connection per task."), &ForceMaxQueryParallelization, false, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomIntVariable( "citus.executor_slow_start_interval", gettext_noop("Time to wait between opening connections to the same worker node"), gettext_noop("When the individual tasks of a multi-shard query take very " "little time, they can often be finished over a single (often " "already cached) connection. To avoid redundantly opening " "additional connections, the executor waits between connection " "attempts for the configured number of milliseconds. At the end " "of the interval, it increases the number of connections it is " "allowed to open next time."), &ExecutorSlowStartInterval, 10, 0, INT_MAX, PGC_USERSET, GUC_UNIT_MS | GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.enable_deadlock_prevention", gettext_noop("Avoids deadlocks by preventing concurrent multi-shard commands"), gettext_noop("Multi-shard modifications such as UPDATE, DELETE, and " "INSERT...SELECT are typically executed in parallel. If multiple " "such commands run concurrently and affect the same rows, then " "they are likely to deadlock. When enabled, this flag prevents " "multi-shard modifications from running concurrently when they " "affect the same shards in order to prevent deadlocks."), &EnableDeadlockPrevention, true, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.enable_ddl_propagation", gettext_noop("Enables propagating DDL statements to worker shards"), NULL, &EnableDDLPropagation, true, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.enable_object_propagation", gettext_noop("Enables propagating object creation for more complex objects, " "schema's will always be created"), NULL, &EnableDependencyCreation, true, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.enable_create_type_propagation", gettext_noop("Enables propagating of CREATE TYPE statements to workers"), NULL, &EnableCreateTypePropagation, true, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.enable_alter_role_propagation", gettext_noop("Enables propagating ALTER ROLE statements to workers (excluding " "ALTER ROLE SET)"), NULL, &EnableAlterRolePropagation, true, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.enable_alter_role_set_propagation", gettext_noop("Enables propagating ALTER ROLE SET statements to workers"), NULL, &EnableAlterRoleSetPropagation, true, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); /* * We shouldn't need this variable after we drop support to PostgreSQL 11 and * below. So, noting it here with PG_VERSION_NUM < PG_VERSION_12 */ DefineCustomBoolVariable( "citus.enable_cte_inlining", gettext_noop("When set to false, CTE inlining feature is disabled"), gettext_noop("This feature is not intended for users. It is developed " "to get consistent regression test outputs between Postgres 11" "and Postgres 12. In Postgres 12+, the user can control the behaviour" "by [NOT] MATERIALIZED keyword on CTEs. However, in PG 11, we cannot do " "that."), &EnableCTEInlining, true, PGC_SUSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomEnumVariable( "citus.propagate_set_commands", gettext_noop("Sets which SET commands are propagated to workers."), NULL, &PropagateSetCommands, PROPSETCMD_NONE, propagate_set_commands_options, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.enable_router_execution", gettext_noop("Enables router execution"), NULL, &EnableRouterExecution, true, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomIntVariable( "citus.shard_count", gettext_noop("Sets the number of shards for a new hash-partitioned table" "created with create_distributed_table()."), NULL, &ShardCount, 32, 1, MAX_SHARD_COUNT, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomIntVariable( "citus.shard_replication_factor", gettext_noop("Sets the replication factor for shards."), gettext_noop("Shards are replicated across nodes according to this " "replication factor. Note that shards read this " "configuration value at sharded table creation time, " "and later reuse the initially read value."), &ShardReplicationFactor, 1, 1, MAX_SHARD_REPLICATION_FACTOR, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomIntVariable( "citus.shard_max_size", gettext_noop("Sets the maximum size a shard will grow before it gets split."), gettext_noop("Shards store table and file data. When the source " "file's size for one shard exceeds this configuration " "value, the database ensures that either a new shard " "gets created, or the current one gets split. Note that " "shards read this configuration value at sharded table " "creation time, and later reuse the initially read value."), &ShardMaxSize, 1048576, 256, INT_MAX, /* max allowed size not set to MAX_KILOBYTES on purpose */ PGC_USERSET, GUC_UNIT_KB | GUC_STANDARD, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.sort_returning", gettext_noop("Sorts the RETURNING clause to get consistent test output"), gettext_noop("This feature is not intended for users. It is developed " "to get consistent regression test outputs. When enabled, " "the RETURNING clause returns the tuples sorted. The sort " "is done for all the entries, starting from the first one." "Finally, the sorting is done in ASC order."), &SortReturning, false, PGC_SUSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomIntVariable( "citus.max_intermediate_result_size", gettext_noop("Sets the maximum size of the intermediate results in KB for " "CTEs and complex subqueries."), NULL, &MaxIntermediateResult, 1048576, -1, MAX_KILOBYTES, PGC_USERSET, GUC_UNIT_KB | GUC_STANDARD, NULL, NULL, NULL); DefineCustomIntVariable( "citus.max_adaptive_executor_pool_size", gettext_noop("Sets the maximum number of connections per worker node used by " "the adaptive executor to execute a multi-shard command"), gettext_noop("The adaptive executor may open multiple connections per worker " "node when running multi-shard commands to parallelize the command " "across multiple cores on the worker. This setting specifies the " "maximum number of connections it will open. The number of " "connections is also bounded by the number of shards on the node. " "This setting can be used to reduce the memory usage of a query " "and allow a higher degree of concurrency when concurrent " "multi-shard queries open too many connections to a worker."), &MaxAdaptiveExecutorPoolSize, 16, 1, INT_MAX, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomIntVariable( "citus.max_shared_pool_size", gettext_noop("Sets the maximum number of connections allowed per worker node " "across all the backends from this node. Setting to -1 disables " "connections throttling. Setting to 0 makes it auto-adjust, meaning " "equal to max_connections on the coordinator."), gettext_noop("As a rule of thumb, the value should be at most equal to the " "max_connections on the remote nodes."), &MaxSharedPoolSize, 0, -1, INT_MAX, PGC_SIGHUP, GUC_SUPERUSER_ONLY, NULL, NULL, MaxSharedPoolSizeGucShowHook); DefineCustomIntVariable( "citus.max_worker_nodes_tracked", gettext_noop("Sets the maximum number of worker nodes that are tracked."), gettext_noop("Worker nodes' network locations, their membership and " "health status are tracked in a shared hash table on " "the master node. This configuration value limits the " "size of the hash table, and consequently the maximum " "number of worker nodes that can be tracked." "Citus keeps some information about the worker nodes " "in the shared memory for certain optimizations. The " "optimizations are enforced up to this number of worker " "nodes. Any additional worker nodes may not benefit from" "the optimizations."), &MaxWorkerNodesTracked, 2048, 1024, INT_MAX, PGC_POSTMASTER, GUC_STANDARD, NULL, NULL, NULL); DefineCustomIntVariable( "citus.remote_task_check_interval", gettext_noop("Sets the frequency at which we check job statuses."), gettext_noop("The master node assigns tasks to workers nodes, and " "then regularly checks with them about each task's " "progress. This configuration value sets the time " "interval between two consequent checks."), &RemoteTaskCheckInterval, 10, 1, INT_MAX, PGC_USERSET, GUC_UNIT_MS | GUC_STANDARD, NULL, NULL, NULL); DefineCustomIntVariable( "citus.task_tracker_delay", gettext_noop("This GUC variable has been deprecated."), NULL, &DeprecatedInt, 200 * MS, 1, 100 * MS_PER_SECOND, PGC_SIGHUP, GUC_UNIT_MS | GUC_STANDARD | GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomIntVariable( "citus.max_cached_conns_per_worker", gettext_noop("Sets the maximum number of connections to cache per worker."), gettext_noop("Each backend opens connections to the workers to query the " "shards. At the end of the transaction, the configurated number " "of connections is kept open to speed up subsequent commands. " "Increasing this value will reduce the latency of multi-shard " "queries, but increases overhead on the workers"), &MaxCachedConnectionsPerWorker, 1, 0, INT_MAX, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomIntVariable( "citus.max_assign_task_batch_size", gettext_noop("This GUC variable has been deprecated."), NULL, &DeprecatedInt, 64, 1, INT_MAX, PGC_USERSET, GUC_STANDARD | GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomIntVariable( "citus.max_tracked_tasks_per_node", gettext_noop("This GUC variable has been deprecated."), NULL, &DeprecatedInt, 1024, 8, INT_MAX, PGC_POSTMASTER, GUC_STANDARD | GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomIntVariable( "citus.repartition_join_bucket_count_per_node", gettext_noop("Sets the bucket size for repartition joins per node"), gettext_noop("Repartition joins create buckets in each node and " "uses those to shuffle data around nodes. "), &RepartitionJoinBucketCountPerNode, 4, 1, INT_MAX, PGC_SIGHUP, GUC_STANDARD | GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomIntVariable( "citus.max_running_tasks_per_node", gettext_noop("This GUC variable has been deprecated."), NULL, &DeprecatedInt, 8, 1, INT_MAX, PGC_SIGHUP, GUC_STANDARD | GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomIntVariable( "citus.partition_buffer_size", gettext_noop("Sets the buffer size to use for partition operations."), gettext_noop("Worker nodes allow for table data to be repartitioned " "into multiple text files, much like Hadoop's Map " "command. This configuration value sets the buffer size " "to use per partition operation. After the buffer fills " "up, we flush the repartitioned data into text files."), &PartitionBufferSize, 8192, 0, (INT_MAX / 1024), /* result stored in int variable */ PGC_USERSET, GUC_UNIT_KB | GUC_STANDARD, NULL, NULL, NULL); DefineCustomIntVariable( "citus.large_table_shard_count", gettext_noop("This variable has been deprecated."), gettext_noop("Consider reference tables instead"), &DeprecatedInt, 4, 1, 10000, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomIntVariable( "citus.limit_clause_row_fetch_count", gettext_noop("Number of rows to fetch per task for limit clause optimization."), gettext_noop("Select queries get partitioned and executed as smaller " "tasks. In some cases, select queries with limit clauses " "may need to fetch all rows from each task to generate " "results. In those cases, and where an approximation would " "produce meaningful results, this configuration value sets " "the number of rows to fetch from each task."), &LimitClauseRowFetchCount, -1, -1, INT_MAX, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomRealVariable( "citus.count_distinct_error_rate", gettext_noop("Desired error rate when calculating count(distinct) " "approximates using the postgresql-hll extension. " "0.0 disables approximations for count(distinct); 1.0 " "provides no guarantees about the accuracy of results."), NULL, &CountDistinctErrorRate, 0.0, 0.0, 1.0, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomEnumVariable( "citus.coordinator_aggregation_strategy", gettext_noop("Sets the strategy for when an aggregate cannot be pushed down. " "'row-gather' will pull up intermediate rows to the coordinator, " "while 'disabled' will error if coordinator aggregation is necessary"), NULL, &CoordinatorAggregationStrategy, COORDINATOR_AGGREGATION_ROW_GATHER, coordinator_aggregation_options, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomEnumVariable( "citus.multi_shard_commit_protocol", gettext_noop("Sets the commit protocol for commands modifying multiple shards."), gettext_noop("When a failure occurs during commands that modify multiple " "shards, two-phase commit is required to ensure data is never lost " "and this is the default. However, changing to 1pc may give small " "performance benefits."), &MultiShardCommitProtocol, COMMIT_PROTOCOL_2PC, shard_commit_protocol_options, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomEnumVariable( "citus.single_shard_commit_protocol", gettext_noop( "Sets the commit protocol for commands modifying a single shards with multiple replicas."), gettext_noop("When a failure occurs during commands that modify multiple " "replicas, two-phase commit is required to ensure data is never lost " "and this is the default. However, changing to 1pc may give small " "performance benefits."), &SingleShardCommitProtocol, COMMIT_PROTOCOL_2PC, shard_commit_protocol_options, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomEnumVariable( "citus.task_assignment_policy", gettext_noop("Sets the policy to use when assigning tasks to worker nodes."), gettext_noop("The master node assigns tasks to worker nodes based on shard " "locations. This configuration value specifies the policy to " "use when making these assignments. The greedy policy aims to " "evenly distribute tasks across worker nodes, first-replica just " "assigns tasks in the order shard placements were created, " "and the round-robin policy assigns tasks to worker nodes in " "a round-robin fashion."), &TaskAssignmentPolicy, TASK_ASSIGNMENT_GREEDY, task_assignment_policy_options, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomEnumVariable( "citus.replication_model", gettext_noop("Sets the replication model to be used for distributed tables."), gettext_noop("Depending upon the execution environment, statement- or streaming-" "based replication modes may be employed. Though most Citus deploy-" "ments will simply use statement replication, hosted and MX-style" "deployments should set this parameter to 'streaming'."), &ReplicationModel, REPLICATION_MODEL_COORDINATOR, replication_model_options, PGC_SUSET, GUC_SUPERUSER_ONLY, NULL, NULL, NULL); DefineCustomEnumVariable( "citus.task_executor_type", gettext_noop("Sets the executor type to be used for distributed queries."), gettext_noop("The master node chooses between two different executor types " "when executing a distributed query.The adaptive executor is " "optimal for simple key-value lookup queries and queries that " "involve aggregations and/or co-located joins on multiple shards. "), &TaskExecutorType, MULTI_EXECUTOR_ADAPTIVE, task_executor_type_options, PGC_USERSET, GUC_STANDARD, WarnIfDeprecatedExecutorUsed, NULL, NULL); DefineCustomBoolVariable( "citus.enable_repartition_joins", gettext_noop("Allows Citus to repartition data between nodes."), NULL, &EnableRepartitionJoins, false, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomEnumVariable( "citus.shard_placement_policy", gettext_noop("Sets the policy to use when choosing nodes for shard placement."), gettext_noop("The master node chooses which worker nodes to place new shards " "on. This configuration value specifies the policy to use when " "selecting these nodes. The local-node-first policy places the " "first replica on the client node and chooses others randomly. " "The round-robin policy aims to distribute shards evenly across " "the cluster by selecting nodes in a round-robin fashion." "The random policy picks all workers randomly."), &ShardPlacementPolicy, SHARD_PLACEMENT_ROUND_ROBIN, shard_placement_policy_options, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomEnumVariable( "citus.use_secondary_nodes", gettext_noop("Sets the policy to use when choosing nodes for SELECT queries."), NULL, &ReadFromSecondaries, USE_SECONDARY_NODES_NEVER, use_secondary_nodes_options, PGC_SU_BACKEND, GUC_STANDARD, NULL, NULL, NULL); DefineCustomEnumVariable( "citus.multi_task_query_log_level", gettext_noop("Sets the level of multi task query execution log messages"), NULL, &MultiTaskQueryLogLevel, CITUS_LOG_LEVEL_OFF, log_level_options, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomEnumVariable( "citus.multi_shard_modify_mode", gettext_noop("Sets the connection type for multi shard modify queries"), NULL, &MultiShardConnectionType, PARALLEL_CONNECTION, multi_shard_modify_connection_options, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomStringVariable( "citus.version", gettext_noop("Shows the Citus library version"), NULL, &CitusVersion, CITUS_VERSION, PGC_INTERNAL, GUC_STANDARD, NULL, NULL, NULL); DefineCustomStringVariable( "citus.cluster_name", gettext_noop("Which cluster this node is a part of"), NULL, &CurrentCluster, "default", PGC_SU_BACKEND, GUC_STANDARD, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.writable_standby_coordinator", gettext_noop("Enables simple DML via a streaming replica of the coordinator"), NULL, &WritableStandbyCoordinator, false, PGC_USERSET, GUC_STANDARD, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.enable_version_checks", gettext_noop("Enables version checks during CREATE/ALTER EXTENSION commands"), NULL, &EnableVersionChecks, true, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.enable_unique_job_ids", gettext_noop("Enables unique job IDs by prepending the local process ID and " "group ID. This should usually be enabled, but can be disabled " "for repeatable output in regression tests."), NULL, &EnableUniqueJobIds, true, PGC_USERSET, GUC_SUPERUSER_ONLY | GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomIntVariable( "citus.next_shard_id", gettext_noop("Set the next shard ID to use in shard creation."), gettext_noop("Shard IDs are normally generated using a sequence. If " "next_shard_id is set to a non-zero value, shard IDs will " "instead be generated by incrementing from the value of " "this GUC and this will be reflected in the GUC. This is " "mainly useful to ensure consistent shard IDs when running " "tests in parallel."), &NextShardId, 0, 0, INT_MAX, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomIntVariable( "citus.next_placement_id", gettext_noop("Set the next placement ID to use in placement creation."), gettext_noop("Placement IDs are normally generated using a sequence. If " "next_placement_id is set to a non-zero value, placement IDs will " "instead be generated by incrementing from the value of " "this GUC and this will be reflected in the GUC. This is " "mainly useful to ensure consistent placement IDs when running " "tests in parallel."), &NextPlacementId, 0, 0, INT_MAX, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomIntVariable( "citus.max_task_string_size", gettext_noop("This GUC variable has been deprecated."), NULL, &DeprecatedInt, 12288, 8192, 65536, PGC_POSTMASTER, GUC_STANDARD | GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.enable_statistics_collection", gettext_noop("Enables sending basic usage statistics to Citus."), gettext_noop("Citus uploads daily anonymous usage reports containing " "rounded node count, shard size, distributed table count, " "and operating system name. This configuration value controls " "whether these reports are sent."), &EnableStatisticsCollection, #if defined(HAVE_LIBCURL) && defined(ENABLE_CITUS_STATISTICS_COLLECTION) true, #else false, #endif PGC_SIGHUP, GUC_SUPERUSER_ONLY, &StatisticsCollectionGucCheckHook, NULL, NULL); DefineCustomStringVariable( "citus.node_conninfo", gettext_noop("Sets parameters used for outbound connections."), NULL, &NodeConninfo, #ifdef USE_SSL "sslmode=require", #else "sslmode=prefer", #endif PGC_SIGHUP, GUC_SUPERUSER_ONLY, NodeConninfoGucCheckHook, NodeConninfoGucAssignHook, NULL); DefineCustomIntVariable( "citus.isolation_test_session_remote_process_id", NULL, NULL, &IsolationTestSessionRemoteProcessID, -1, -1, INT_MAX, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomIntVariable( "citus.isolation_test_session_process_id", NULL, NULL, &IsolationTestSessionProcessID, -1, -1, INT_MAX, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomBoolVariable( "citus.replicate_reference_tables_on_activate", NULL, NULL, &ReplicateReferenceTablesOnActivate, true, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); DefineCustomEnumVariable( "citus.explain_analyze_sort_method", gettext_noop("Sets the sorting method for EXPLAIN ANALYZE queries."), gettext_noop("This parameter is intended for testing. It is developed " "to get consistent regression test outputs. When it is set " "to 'time', EXPLAIN ANALYZE output is sorted by execution " "duration on workers. When it is set to 'taskId', it is " "sorted by task id. By default, it is set to 'time'; but " "in regression tests, it's set to 'taskId' for consistency."), &ExplainAnalyzeSortMethod, EXPLAIN_ANALYZE_SORT_BY_TIME, explain_analyze_sort_method_options, PGC_USERSET, GUC_NO_SHOW_ALL, NULL, NULL, NULL); /* warn about config items in the citus namespace that are not registered above */ EmitWarningsOnPlaceholders("citus"); } /* * We don't want to allow values less than 1.0. However, we define -1 as the value to disable * distributed deadlock checking. Here we enforce our special constraint. */ static bool ErrorIfNotASuitableDeadlockFactor(double *newval, void **extra, GucSource source) { if (*newval <= 1.0 && *newval != -1.0) { ereport(WARNING, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg( "citus.distributed_deadlock_detection_factor cannot be less than 1. " "To disable distributed deadlock detection set the value to -1."))); return false; } return true; } /* * WarnIfDeprecatedExecutorUsed prints a warning and sets the config value to * adaptive executor (a.k.a., ignores real-time executor). */ static bool WarnIfDeprecatedExecutorUsed(int *newval, void **extra, GucSource source) { if (*newval == DUMMY_REAL_TIME_EXECUTOR_ENUM_VALUE) { ereport(WARNING, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("Ignoring the setting, real-time executor is " "deprecated"))); /* adaptive executor is superset of real-time, so switch to that */ *newval = MULTI_EXECUTOR_ADAPTIVE; } return true; } /* * NoticeIfSubqueryPushdownEnabled prints a notice when a user sets * citus.subquery_pushdown to ON. It doesn't print the notice if the * value is already true. */ static bool NoticeIfSubqueryPushdownEnabled(bool *newval, void **extra, GucSource source) { /* notice only when the value changes */ if (*newval == true && SubqueryPushdown == false) { ereport(NOTICE, (errcode(ERRCODE_WARNING_DEPRECATED_FEATURE), errmsg("Setting citus.subquery_pushdown flag is " "discouraged becuase it forces the planner " "to pushdown certain queries, skipping " "relevant correctness checks."), errdetail( "When enabled, the planner skips many correctness checks " "for subqueries and pushes down the queries to shards as-is. " "It means that the queries are likely to return wrong results " "unless the user is absolutely sure that pushing down the " "subquery is safe. This GUC is maintained only for backward " "compatibility, no new users are supposed to use it. The planner " "is capable of pushing down as much computation as possible to the " "shards depending on the query."))); } return true; } /* * NodeConninfoGucCheckHook ensures conninfo settings are in the expected form * and that the keywords of all non-null settings are on a allowlist devised to * keep users from setting options that may result in confusion. */ static bool NodeConninfoGucCheckHook(char **newval, void **extra, GucSource source) { /* this array _must_ be kept in an order usable by bsearch */ const char *allowedConninfoKeywords[] = { "application_name", "connect_timeout", #if defined(ENABLE_GSS) && defined(ENABLE_SSPI) "gsslib", #endif "keepalives", "keepalives_count", "keepalives_idle", "keepalives_interval", #if defined(ENABLE_GSS) || defined(ENABLE_SSPI) "krbsrvname", #endif "sslcompression", "sslcrl", "sslmode", "sslrootcert" }; char *errorMsg = NULL; bool conninfoValid = CheckConninfo(*newval, allowedConninfoKeywords, lengthof(allowedConninfoKeywords), &errorMsg); if (!conninfoValid) { GUC_check_errdetail("%s", errorMsg); } return conninfoValid; } /* * NodeConninfoGucAssignHook is the assignment hook for the node_conninfo GUC * variable. Though this GUC is a "string", we actually parse it as a non-URI * PQconninfo key/value setting, storing the resultant PQconninfoOption values * using the public functions in connection_configuration.c. */ static void NodeConninfoGucAssignHook(const char *newval, void *extra) { if (newval == NULL) { newval = ""; } if (strcmp(newval, NodeConninfo) == 0) { /* It did not change, no need to do anything */ return; } PQconninfoOption *optionArray = PQconninfoParse(newval, NULL); if (optionArray == NULL) { ereport(FATAL, (errmsg("cannot parse node_conninfo value"), errdetail("The GUC check hook should prevent " "all malformed values."))); } ResetConnParams(); for (PQconninfoOption *option = optionArray; option->keyword != NULL; option++) { if (option->val == NULL || option->val[0] == '\0') { continue; } AddConnParam(option->keyword, option->val); } PQconninfoFree(optionArray); /* * Mark all connections for shutdown, since they have been opened using old * connection settings. This is mostly important when changing SSL * parameters, otherwise these would not be applied and connections could * be unencrypted when the user doesn't want that. */ CloseAllConnectionsAfterTransaction(); } /* * MaxSharedPoolSizeGucShowHook overrides the value that is shown to the * user when the default value has not been set. */ static const char * MaxSharedPoolSizeGucShowHook(void) { StringInfo newvalue = makeStringInfo(); if (MaxSharedPoolSize == 0) { appendStringInfo(newvalue, "%d", GetMaxSharedPoolSize()); } else { appendStringInfo(newvalue, "%d", MaxSharedPoolSize); } return (const char *) newvalue->data; } static bool StatisticsCollectionGucCheckHook(bool *newval, void **extra, GucSource source) { #ifdef HAVE_LIBCURL return true; #else /* if libcurl is not installed, only accept false */ if (*newval) { GUC_check_errcode(ERRCODE_FEATURE_NOT_SUPPORTED); GUC_check_errdetail("Citus was compiled without libcurl support."); return false; } else { return true; } #endif }