/*------------------------------------------------------------------------- * * treasuredata_fdw.c * Foreign-data wrapper for Treasure Data * * Portions Copyright (c) 2016, Mitsunori Komatsu * * IDENTIFICATION * treasuredata_fdw.c * *------------------------------------------------------------------------- */ #include "postgres.h" #include "treasuredata_fdw.h" #include "bridge.h" #include "access/htup_details.h" #include "access/sysattr.h" #include "commands/defrem.h" #include "commands/explain.h" #include "commands/vacuum.h" #include "foreign/fdwapi.h" #include "funcapi.h" #include "miscadmin.h" #include "nodes/makefuncs.h" #include "nodes/nodeFuncs.h" #include "optimizer/cost.h" #include "optimizer/pathnode.h" #include "optimizer/paths.h" #include "optimizer/planmain.h" #include "optimizer/prep.h" #include "optimizer/restrictinfo.h" #include "optimizer/var.h" #include "parser/parsetree.h" #include "utils/builtins.h" #include "utils/guc.h" #include "utils/lsyscache.h" #include "utils/memutils.h" #include "utils/rel.h" PG_MODULE_MAGIC; extern Datum treasuredata_fdw_handler(PG_FUNCTION_ARGS); PG_FUNCTION_INFO_V1(treasuredata_fdw_handler); /* Default CPU cost to start up a foreign query. */ #define DEFAULT_FDW_STARTUP_COST 100.0 /* Default CPU cost to process 1 row (above and beyond cpu_tuple_cost). */ #define DEFAULT_FDW_TUPLE_COST 0.01 /* * FDW-specific planner information kept in RelOptInfo.fdw_private for a * foreign table. This information is collected by treasuredataGetForeignRelSize. */ typedef struct TdFdwRelationInfo { /* baserestrictinfo clauses, broken down into safe and unsafe subsets. */ List *remote_conds; List *local_conds; /* Bitmap of attr numbers we need to fetch from the remote server. */ Bitmapset *attrs_used; /* Cost and selectivity of local_conds. */ QualCost local_conds_cost; Selectivity local_conds_sel; /* Estimated size and cost for a scan with baserestrictinfo quals. */ double rows; int width; Cost startup_cost; Cost total_cost; /* Options extracted from catalogs. */ Cost fdw_startup_cost; Cost fdw_tuple_cost; /* Cached catalog information. */ ForeignTable *table; ForeignServer *server; /* Query engine type */ QueryEngineType query_engine_type; } TdFdwRelationInfo; /* * Indexes of FDW-private information stored in fdw_private lists. * * We store various information in ForeignScan.fdw_private to pass it from * planner to executor. Currently we store: * * 1) SELECT statement text to be sent to the remote server * 2) Integer list of attribute numbers retrieved by the SELECT * * These items are indexed with the enum FdwScanPrivateIndex, so an item * can be fetched with list_nth(). For example, to get the SELECT statement: * sql = strVal(list_nth(fdw_private, FdwScanPrivateSelectSql)); */ enum FdwScanPrivateIndex { /* SQL statement to execute remotely (as a String node) */ FdwScanPrivateSelectSql, /* Integer list of attribute numbers retrieved by the SELECT */ FdwScanPrivateRetrievedAttrs, FdwScanPrivateForeignTable }; /* * Similarly, this enum describes what's kept in the fdw_private list for * a ModifyTable node referencing a treasuredata_fdw foreign table. We store: * * 1) INSERT/UPDATE/DELETE statement text to be sent to the remote server * 2) Integer list of target attribute numbers for INSERT/UPDATE * (NIL for a DELETE) * 3) Boolean flag showing if the remote query has a RETURNING clause * 4) Integer list of attribute numbers retrieved by RETURNING, if any */ enum FdwModifyPrivateIndex { /* SQL statement to execute remotely (as a String node) */ FdwModifyPrivateUpdateSql, /* Integer list of target attribute numbers for INSERT/UPDATE */ FdwModifyPrivateTargetAttnums, /* has-returning flag (as an integer Value node) */ FdwModifyPrivateHasReturning, /* Integer list of attribute numbers retrieved by RETURNING */ FdwModifyPrivateRetrievedAttrs }; /* * Execution state of a foreign scan using treasuredata_fdw. */ typedef struct TdFdwScanState { Relation rel; /* relcache entry for the foreign table */ AttInMetadata *attinmeta; /* attribute datatype conversion metadata */ /* extracted fdw_private data */ char *query; /* text of SELECT command */ List *retrieved_attrs; /* list of retrieved attribute numbers */ /* for remote query execution */ void *td_client; int numParams; /* number of parameters passed to query */ FmgrInfo *param_flinfo; /* output conversion functions for them */ List *param_exprs; /* executable expressions for param values */ const char **param_values; /* textual values of query parameters */ /* for storing result tuples */ HeapTuple *tuples; /* array of currently-retrieved tuples */ int num_tuples; /* # of tuples in array */ int next_tuple; /* index of next one to return */ /* batch-level state, for optimizing rewinds and avoiding useless fetch */ int fetch_ct_2; /* Min(# of fetches done, 2) */ bool eof_reached; /* true if last fetch reached EOF */ /* working memory contexts */ MemoryContext batch_cxt; /* context holding current batch of tuples */ MemoryContext temp_cxt; /* context for per-tuple temporary data */ /* Cached catalog information. */ ForeignTable *table; } TdFdwScanState; #if 0 /* * Execution state of a foreign insert/update/delete operation. */ typedef struct TdFdwModifyState { Relation rel; /* relcache entry for the foreign table */ AttInMetadata *attinmeta; /* attribute datatype conversion metadata */ /* for remote query execution */ PGconn *conn; /* connection for the scan */ char *p_name; /* name of prepared statement, if created */ /* extracted fdw_private data */ char *query; /* text of INSERT/UPDATE/DELETE command */ List *target_attrs; /* list of target attribute numbers */ bool has_returning; /* is there a RETURNING clause? */ List *retrieved_attrs; /* attr numbers retrieved by RETURNING */ /* info about parameters for prepared statement */ AttrNumber ctidAttno; /* attnum of input resjunk ctid column */ int p_nums; /* number of parameters to transmit */ FmgrInfo *p_flinfo; /* output conversion functions for them */ /* working memory context */ MemoryContext temp_cxt; /* context for per-tuple temporary data */ } TdFdwModifyState; /* * Workspace for analyzing a foreign table. */ typedef struct TdFdwAnalyzeState { Relation rel; /* relcache entry for the foreign table */ AttInMetadata *attinmeta; /* attribute datatype conversion metadata */ List *retrieved_attrs; /* attr numbers retrieved by query */ /* collected sample rows */ HeapTuple *rows; /* array of size targrows */ int targrows; /* target # of sample rows */ int numrows; /* # of sample rows collected */ /* for random sampling */ double samplerows; /* # of rows fetched */ double rowstoskip; /* # of rows to skip before next sample */ ReservoirStateData rstate; /* state for reservoir sampling */ /* working memory contexts */ MemoryContext anl_cxt; /* context for per-analyze lifespan data */ MemoryContext temp_cxt; /* context for per-tuple temporary data */ } TdFdwAnalyzeState; #endif /* * Identify the attribute where data conversion fails. */ typedef struct ConversionLocation { Relation rel; /* foreign table's relcache entry */ AttrNumber cur_attno; /* attribute number being processed, or 0 */ } ConversionLocation; /* Callback argument for ec_member_matches_foreign */ typedef struct { Expr *current; /* current expr, or NULL if not yet found */ List *already_used; /* expressions already dealt with */ } ec_member_foreign_arg; /* * FDW callback routines */ static void treasuredataGetForeignRelSize(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid); static void treasuredataGetForeignPaths(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid); static ForeignScan *treasuredataGetForeignPlan(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid, ForeignPath *best_path, List *tlist, List *scan_clauses, Plan *outer_plan); static void treasuredataBeginForeignScan(ForeignScanState *node, int eflags); static TupleTableSlot *treasuredataIterateForeignScan(ForeignScanState *node); // static void treasuredataReScanForeignScan(ForeignScanState *node); static void treasuredataEndForeignScan(ForeignScanState *node); #if 0 static void treasuredataAddForeignUpdateTargets(Query *parsetree, RangeTblEntry *target_rte, Relation target_relation); static List *treasuredataPlanForeignModify(PlannerInfo *root, ModifyTable *plan, Index resultRelation, int subplan_index); static void treasuredataBeginForeignModify(ModifyTableState *mtstate, ResultRelInfo *resultRelInfo, List *fdw_private, int subplan_index, int eflags); static TupleTableSlot *treasuredataExecForeignInsert(EState *estate, ResultRelInfo *resultRelInfo, TupleTableSlot *slot, TupleTableSlot *planSlot); static TupleTableSlot *treasuredataExecForeignUpdate(EState *estate, ResultRelInfo *resultRelInfo, TupleTableSlot *slot, TupleTableSlot *planSlot); static TupleTableSlot *treasuredataExecForeignDelete(EState *estate, ResultRelInfo *resultRelInfo, TupleTableSlot *slot, TupleTableSlot *planSlot); static void treasuredataEndForeignModify(EState *estate, ResultRelInfo *resultRelInfo); static int treasuredataIsForeignRelUpdatable(Relation rel); static void treasuredataExplainForeignScan(ForeignScanState *node, ExplainState *es); static void treasuredataExplainForeignModify(ModifyTableState *mtstate, ResultRelInfo *rinfo, List *fdw_private, int subplan_index, ExplainState *es); static bool treasuredataAnalyzeForeignTable(Relation relation, AcquireSampleRowsFunc *func, BlockNumber *totalpages); static List *treasuredataImportForeignSchema(ImportForeignSchemaStmt *stmt, Oid serverOid); #endif /* * Helper functions */ static void estimate_path_cost_size(PlannerInfo *root, RelOptInfo *baserel, List *join_conds, double *p_rows, int *p_width, Cost *p_startup_cost, Cost *p_total_cost); #if 0 static bool ec_member_matches_foreign(PlannerInfo *root, RelOptInfo *rel, EquivalenceClass *ec, EquivalenceMember *em, void *arg); static void fetch_more_data(ForeignScanState *node); static void close_cursor(PGconn *conn, unsigned int cursor_number); static void prepare_foreign_modify(TdFdwModifyState *fmstate); static const char **convert_prep_stmt_params(TdFdwModifyState *fmstate, ItemPointer tupleid, TupleTableSlot *slot); static void store_returning_result(TdFdwModifyState *fmstate, TupleTableSlot *slot, PGresult *res); static int treasuredataAcquireSampleRowsFunc(Relation relation, int elevel, HeapTuple *rows, int targrows, double *totalrows, double *totaldeadrows); static void analyze_row_processor(PGresult *res, int row, TdFdwAnalyzeState *astate); #endif static HeapTuple make_tuple_from_result_row(void *td_client, Relation rel, AttInMetadata *attinmeta, List *retrieved_attrs, MemoryContext temp_context); static void conversion_error_callback(void *arg); /* * Foreign-data wrapper handler function: return a struct with pointers * to my callback routines. */ Datum treasuredata_fdw_handler(PG_FUNCTION_ARGS) { FdwRoutine *routine = makeNode(FdwRoutine); /* Functions for scanning foreign tables */ routine->GetForeignRelSize = treasuredataGetForeignRelSize; routine->GetForeignPaths = treasuredataGetForeignPaths; routine->GetForeignPlan = treasuredataGetForeignPlan; routine->BeginForeignScan = treasuredataBeginForeignScan; routine->IterateForeignScan = treasuredataIterateForeignScan; // routine->ReScanForeignScan = treasuredataReScanForeignScan; routine->EndForeignScan = treasuredataEndForeignScan; #if 0 /* Functions for updating foreign tables */ routine->AddForeignUpdateTargets = treasuredataAddForeignUpdateTargets; routine->PlanForeignModify = treasuredataPlanForeignModify; routine->BeginForeignModify = treasuredataBeginForeignModify; routine->ExecForeignInsert = treasuredataExecForeignInsert; routine->ExecForeignUpdate = treasuredataExecForeignUpdate; routine->ExecForeignDelete = treasuredataExecForeignDelete; routine->EndForeignModify = treasuredataEndForeignModify; routine->IsForeignRelUpdatable = treasuredataIsForeignRelUpdatable; /* Support functions for EXPLAIN */ routine->ExplainForeignScan = treasuredataExplainForeignScan; routine->ExplainForeignModify = treasuredataExplainForeignModify; /* Support functions for ANALYZE */ routine->AnalyzeForeignTable = treasuredataAnalyzeForeignTable; /* Support functions for IMPORT FOREIGN SCHEMA */ routine->ImportForeignSchema = treasuredataImportForeignSchema; #endif PG_RETURN_POINTER(routine); } /* * treasuredataGetForeignRelSize * Estimate # of rows and width of the result of the scan * * We should consider the effect of all baserestrictinfo clauses here, but * not any join clauses. */ static void treasuredataGetForeignRelSize(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid) { TdFdwRelationInfo *fpinfo; ListCell *lc; /* * We use TdFdwRelationInfo to pass various information to subsequent * functions. */ fpinfo = (TdFdwRelationInfo *) palloc0(sizeof(TdFdwRelationInfo)); baserel->fdw_private = (void *) fpinfo; /* Look up foreign-table catalog info. */ fpinfo->table = GetForeignTable(foreigntableid); fpinfo->server = GetForeignServer(fpinfo->table->serverid); { TdFdwOption fdw_option; ExtractFdwOptions(fpinfo->table, &fdw_option); if (strcmp(fdw_option.query_engine, "presto") == 0) fpinfo->query_engine_type = QUERY_ENGINE_PRESTO; else fpinfo->query_engine_type = QUERY_ENGINE_HIVE; } fpinfo->fdw_startup_cost = DEFAULT_FDW_STARTUP_COST; fpinfo->fdw_tuple_cost = DEFAULT_FDW_TUPLE_COST; /* * Identify which baserestrictinfo clauses can be sent to the remote * server and which can't. */ classifyConditions(root, baserel, baserel->baserestrictinfo, &fpinfo->remote_conds, &fpinfo->local_conds); /* * Identify which attributes will need to be retrieved from the remote * server. These include all attrs needed for joins or final output, plus * all attrs used in the local_conds. (Note: if we end up using a * parameterized scan, it's possible that some of the join clauses will be * sent to the remote and thus we wouldn't really need to retrieve the * columns used in them. Doesn't seem worth detecting that case though.) */ fpinfo->attrs_used = NULL; #if PG_VERSION_NUM >= 90600 pull_varattnos((Node *) baserel->reltarget->exprs, baserel->relid, &fpinfo->attrs_used); #else pull_varattnos((Node *) baserel->reltargetlist, baserel->relid, &fpinfo->attrs_used); #endif foreach(lc, fpinfo->local_conds) { RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc); pull_varattnos((Node *) rinfo->clause, baserel->relid, &fpinfo->attrs_used); } /* * Compute the selectivity and cost of the local_conds, so we don't have * to do it over again for each path. The best we can do for these * conditions is to estimate selectivity on the basis of local statistics. */ fpinfo->local_conds_sel = clauselist_selectivity(root, fpinfo->local_conds, baserel->relid, JOIN_INNER, NULL); cost_qual_eval(&fpinfo->local_conds_cost, fpinfo->local_conds, root); /* * Estimate using whatever statistics we have locally, in a way similar * to ordinary tables. * * If the foreign table has never been ANALYZEd, it will have relpages * and reltuples equal to zero, which most likely has nothing to do * with reality. We can't do a whole lot about that if we're not * allowed to consult the remote server, but we can use a hack similar * to plancat.c's treatment of empty relations: use a minimum size * estimate of 10 pages, and divide by the column-datatype-based width * estimate to get the corresponding number of tuples. */ if (baserel->pages == 0 && baserel->tuples == 0) { baserel->pages = 10; baserel->tuples = #if PG_VERSION_NUM >= 90600 (10 * BLCKSZ) / (baserel->reltarget->width + MAXALIGN(SizeofHeapTupleHeader)); #elif PG_VERSION_NUM >= 90500 (10 * BLCKSZ) / (baserel->width + MAXALIGN(SizeofHeapTupleHeader)); #else (10 * BLCKSZ) / (baserel->width + sizeof(HeapTupleHeaderData)); #endif } /* Estimate baserel size as best we can with local statistics. */ set_baserel_size_estimates(root, baserel); /* Fill in basically-bogus cost estimates for use later. */ estimate_path_cost_size(root, baserel, NIL, &fpinfo->rows, &fpinfo->width, &fpinfo->startup_cost, &fpinfo->total_cost); } /* * treasuredataGetForeignPaths * Create possible scan paths for a scan on the foreign table */ static void treasuredataGetForeignPaths(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid) { TdFdwRelationInfo *fpinfo = (TdFdwRelationInfo *) baserel->fdw_private; ForeignPath *path; /* * Create simplest ForeignScan path node and add it to baserel. This path * corresponds to SeqScan path of regular tables (though depending on what * baserestrict conditions we were able to send to remote, there might * actually be an indexscan happening there). We already did all the work * to estimate cost and size of this path. */ path = create_foreignscan_path(root, baserel, #if PG_VERSION_NUM >= 90600 NULL, /* default pathtarget */ #endif fpinfo->rows, fpinfo->startup_cost, fpinfo->total_cost, NIL, /* no pathkeys */ NULL, /* no outer rel either */ #if PG_VERSION_NUM >= 90500 NULL, /* no extra plan */ #endif NIL); /* no fdw_private list */ add_path(baserel, (Path *) path); } /* * treasuredataGetForeignPlan * Create ForeignScan plan node which implements selected best path */ static ForeignScan * treasuredataGetForeignPlan(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid, ForeignPath *best_path, List *tlist, List *scan_clauses, Plan *outer_plan) { TdFdwRelationInfo *fpinfo = (TdFdwRelationInfo *) baserel->fdw_private; Index scan_relid = baserel->relid; List *fdw_private; List *remote_conds = NIL; List *remote_exprs = NIL; List *local_exprs = NIL; List *params_list = NIL; List *retrieved_attrs; StringInfoData sql; ListCell *lc; /* * Separate the scan_clauses into those that can be executed remotely and * those that can't. baserestrictinfo clauses that were previously * determined to be safe or unsafe by classifyConditions are shown in * fpinfo->remote_conds and fpinfo->local_conds. Anything else in the * scan_clauses list will be a join clause, which we have to check for * remote-safety. * * Note: the join clauses we see here should be the exact same ones * previously examined by treasuredataGetForeignPaths. Possibly it'd be worth * passing forward the classification work done then, rather than * repeating it here. * * This code must match "extract_actual_clauses(scan_clauses, false)" * except for the additional decision about remote versus local execution. * Note however that we don't strip the RestrictInfo nodes from the * remote_conds list, since appendWhereClause expects a list of * RestrictInfos. */ foreach(lc, scan_clauses) { RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc); Assert(IsA(rinfo, RestrictInfo)); /* Ignore any pseudoconstants, they're dealt with elsewhere */ if (rinfo->pseudoconstant) continue; if (list_member_ptr(fpinfo->remote_conds, rinfo)) { remote_conds = lappend(remote_conds, rinfo); remote_exprs = lappend(remote_exprs, rinfo->clause); } else if (list_member_ptr(fpinfo->local_conds, rinfo)) local_exprs = lappend(local_exprs, rinfo->clause); else if (is_foreign_expr(root, baserel, rinfo->clause)) { remote_conds = lappend(remote_conds, rinfo); remote_exprs = lappend(remote_exprs, rinfo->clause); } else local_exprs = lappend(local_exprs, rinfo->clause); } /* * Build the query string to be sent for execution, and identify * expressions to be sent as parameters. */ initStringInfo(&sql); deparseSelectSql(&sql, root, baserel, fpinfo->attrs_used, &retrieved_attrs, fpinfo->query_engine_type); if (remote_conds) appendWhereClause(&sql, root, baserel, remote_conds, true, ¶ms_list, fpinfo->query_engine_type); /* * Add FOR UPDATE/SHARE if appropriate. We apply locking during the * initial row fetch, rather than later on as is done for local tables. * The extra roundtrips involved in trying to duplicate the local * semantics exactly don't seem worthwhile (see also comments for * RowMarkType). * * Note: because we actually run the query as a cursor, this assumes that * DECLARE CURSOR ... FOR UPDATE is supported, which it isn't before 8.3. */ if (baserel->relid == root->parse->resultRelation && (root->parse->commandType == CMD_UPDATE || root->parse->commandType == CMD_DELETE)) { elog(ERROR, "SELECT FOR UPDATE isn't supported"); } #if PG_VERSION_NUM >= 90500 else { PlanRowMark *rc = get_plan_rowmark(root->rowMarks, baserel->relid); if (rc) { /* * Relation is specified as a FOR UPDATE/SHARE target, so handle * that. (But we could also see LCS_NONE, meaning this isn't a * target relation after all.) * * For now, just ignore any [NO] KEY specification, since (a) it's * not clear what that means for a remote table that we don't have * complete information about, and (b) it wouldn't work anyway on * older remote servers. Likewise, we don't worry about NOWAIT. */ switch (rc->strength) { case LCS_NONE: /* No locking needed */ break; case LCS_FORKEYSHARE: case LCS_FORSHARE: elog(ERROR, "SELECT FOR SHARE isn't supported"); break; case LCS_FORNOKEYUPDATE: case LCS_FORUPDATE: elog(ERROR, "SELECT FOR UPDATE isn't supported"); break; } } } #endif /* * Build the fdw_private list that will be available to the executor. * Items in the list must match enum FdwScanPrivateIndex, above. */ fdw_private = list_make3(makeString(sql.data), retrieved_attrs, fpinfo->table ); /* * Create the ForeignScan node from target list, local filtering * expressions, remote parameter expressions, and FDW private information. * * Note that the remote parameter expressions are stored in the fdw_exprs * field of the finished plan node; we can't keep them in private state * because then they wouldn't be subject to later planner processing. */ return make_foreignscan(tlist , local_exprs , scan_relid , params_list , fdw_private #if PG_VERSION_NUM >= 90500 , NIL /* no custom tlist */ , remote_exprs , outer_plan #endif ); } /* * treasuredataBeginForeignScan * Initiate an executor scan of a foreign PostgreSQL table. */ static void treasuredataBeginForeignScan(ForeignScanState *node, int eflags) { ForeignScan *fsplan = (ForeignScan *) node->ss.ps.plan; EState *estate = node->ss.ps.state; TdFdwScanState *fsstate; int numParams; int i; ListCell *lc; /* * Do nothing in EXPLAIN (no ANALYZE) case. node->fdw_state stays NULL. */ if (eflags & EXEC_FLAG_EXPLAIN_ONLY) return; /* * We'll save private state in node->fdw_state. */ fsstate = (TdFdwScanState *) palloc0(sizeof(TdFdwScanState)); node->fdw_state = (void *) fsstate; /* Get info about foreign table. */ fsstate->rel = node->ss.ss_currentRelation; fsstate->td_client = NULL; /* Get private info created by planner functions. */ fsstate->query = strVal(list_nth(fsplan->fdw_private, FdwScanPrivateSelectSql)); fsstate->retrieved_attrs = (List *) list_nth(fsplan->fdw_private, FdwScanPrivateRetrievedAttrs); fsstate->table = (ForeignTable *) list_nth(fsplan->fdw_private, FdwScanPrivateForeignTable); /* Create contexts for batches of tuples and per-tuple temp workspace. */ fsstate->batch_cxt = AllocSetContextCreate(estate->es_query_cxt, "treasuredata_fdw tuple data", ALLOCSET_DEFAULT_MINSIZE, ALLOCSET_DEFAULT_INITSIZE, ALLOCSET_DEFAULT_MAXSIZE); fsstate->temp_cxt = AllocSetContextCreate(estate->es_query_cxt, "treasuredata_fdw temporary data", ALLOCSET_SMALL_MINSIZE, ALLOCSET_SMALL_INITSIZE, ALLOCSET_SMALL_MAXSIZE); /* Get info we'll need for input data conversion. */ fsstate->attinmeta = TupleDescGetAttInMetadata(RelationGetDescr(fsstate->rel)); /* Prepare for output conversion of parameters used in remote query. */ numParams = list_length(fsplan->fdw_exprs); fsstate->numParams = numParams; fsstate->param_flinfo = (FmgrInfo *) palloc0(sizeof(FmgrInfo) * numParams); i = 0; foreach(lc, fsplan->fdw_exprs) { Node *param_expr = (Node *) lfirst(lc); Oid typefnoid; bool isvarlena; getTypeOutputInfo(exprType(param_expr), &typefnoid, &isvarlena); fmgr_info(typefnoid, &fsstate->param_flinfo[i]); i++; } /* * Prepare remote-parameter expressions for evaluation. (Note: in * practice, we expect that all these expressions will be just Params, so * we could possibly do something more efficient than using the full * expression-eval machinery for this. But probably there would be little * benefit, and it'd require treasuredata_fdw to know more than is desirable * about Param evaluation.) */ fsstate->param_exprs = (List *) ExecInitExpr((Expr *) fsplan->fdw_exprs, (PlanState *) node); /* * Allocate buffer for text form of query parameters, if any. */ if (numParams > 0) fsstate->param_values = (const char **) palloc0(numParams * sizeof(char *)); else fsstate->param_values = NULL; } /* * treasuredataIterateForeignScan * Retrieve next row from the result set, or clear tuple slot to indicate * EOF. */ static TupleTableSlot * treasuredataIterateForeignScan(ForeignScanState *node) { TdFdwScanState *fsstate = (TdFdwScanState *) node->fdw_state; TupleTableSlot *slot = node->ss.ss_ScanTupleSlot; HeapTuple tuple;; if (fsstate->td_client == NULL) { TdFdwOption fdw_option; ExtractFdwOptions(fsstate->table, &fdw_option); fsstate->td_client = issueQuery( fdw_option.apikey, fdw_option.endpoint, fdw_option.query_engine, fdw_option.database, fsstate->query); } tuple = make_tuple_from_result_row( fsstate->td_client, fsstate->rel, fsstate->attinmeta, fsstate->retrieved_attrs, fsstate->temp_cxt); if (tuple == NULL) { return ExecClearTuple(slot); } /* * Return the next tuple. */ ExecStoreTuple(tuple, slot, InvalidBuffer, false); return slot; } #if 0 /* * treasuredataReScanForeignScan * Restart the scan. */ static void treasuredataReScanForeignScan(ForeignScanState *node) { TdFdwScanState *fsstate = (TdFdwScanState *) node->fdw_state; char sql[64]; PGresult *res; /* If we haven't created the cursor yet, nothing to do. */ if (!fsstate->cursor_exists) return; /* * If any internal parameters affecting this node have changed, we'd * better destroy and recreate the cursor. Otherwise, rewinding it should * be good enough. If we've only fetched zero or one batch, we needn't * even rewind the cursor, just rescan what we have. */ if (node->ss.ps.chgParam != NULL) { fsstate->cursor_exists = false; snprintf(sql, sizeof(sql), "CLOSE c%u", fsstate->cursor_number); } else if (fsstate->fetch_ct_2 > 1) { snprintf(sql, sizeof(sql), "MOVE BACKWARD ALL IN c%u", fsstate->cursor_number); } else { /* Easy: just rescan what we already have in memory, if anything */ fsstate->next_tuple = 0; return; } /* * We don't use a PG_TRY block here, so be careful not to throw error * without releasing the PGresult. */ res = PQexec(fsstate->conn, sql); if (PQresultStatus(res) != PGRES_COMMAND_OK) pgfdw_report_error(ERROR, res, fsstate->conn, true, sql); PQclear(res); /* Now force a fresh FETCH. */ fsstate->tuples = NULL; fsstate->num_tuples = 0; fsstate->next_tuple = 0; fsstate->fetch_ct_2 = 0; fsstate->eof_reached = false; } #endif /* * treasuredataEndForeignScan * Finish scanning foreign table and dispose objects used for this scan */ static void treasuredataEndForeignScan(ForeignScanState *node) { TdFdwScanState *fsstate = (TdFdwScanState *) node->fdw_state; /* if fsstate is NULL, we are in EXPLAIN; nothing to do */ if (fsstate == NULL) return; releaseResource(fsstate->td_client); fsstate->td_client = NULL; /* MemoryContexts will be deleted automatically. */ } #if 0 /* * treasuredataAddForeignUpdateTargets * Add resjunk column(s) needed for update/delete on a foreign table */ static void treasuredataAddForeignUpdateTargets(Query *parsetree, RangeTblEntry *target_rte, Relation target_relation) { Var *var; const char *attrname; TargetEntry *tle; /* * In treasuredata_fdw, what we need is the ctid, same as for a regular table. */ /* Make a Var representing the desired value */ var = makeVar(parsetree->resultRelation, SelfItemPointerAttributeNumber, TIDOID, -1, InvalidOid, 0); /* Wrap it in a resjunk TLE with the right name ... */ attrname = "ctid"; tle = makeTargetEntry((Expr *) var, list_length(parsetree->targetList) + 1, pstrdup(attrname), true); /* ... and add it to the query's targetlist */ parsetree->targetList = lappend(parsetree->targetList, tle); } /* * treasuredataPlanForeignModify * Plan an insert/update/delete operation on a foreign table * * Note: currently, the plan tree generated for UPDATE/DELETE will always * include a ForeignScan that retrieves ctids (using SELECT FOR UPDATE) * and then the ModifyTable node will have to execute individual remote * UPDATE/DELETE commands. If there are no local conditions or joins * needed, it'd be better to let the scan node do UPDATE/DELETE RETURNING * and then do nothing at ModifyTable. Room for future optimization ... */ static List * treasuredataPlanForeignModify(PlannerInfo *root, ModifyTable *plan, Index resultRelation, int subplan_index) { CmdType operation = plan->operation; RangeTblEntry *rte = planner_rt_fetch(resultRelation, root); Relation rel; StringInfoData sql; List *targetAttrs = NIL; List *returningList = NIL; List *retrieved_attrs = NIL; bool doNothing = false; initStringInfo(&sql); /* * Core code already has some lock on each rel being planned, so we can * use NoLock here. */ rel = heap_open(rte->relid, NoLock); /* * In an INSERT, we transmit all columns that are defined in the foreign * table. In an UPDATE, we transmit only columns that were explicitly * targets of the UPDATE, so as to avoid unnecessary data transmission. * (We can't do that for INSERT since we would miss sending default values * for columns not listed in the source statement.) */ if (operation == CMD_INSERT) { TupleDesc tupdesc = RelationGetDescr(rel); int attnum; for (attnum = 1; attnum <= tupdesc->natts; attnum++) { Form_pg_attribute attr = tupdesc->attrs[attnum - 1]; if (!attr->attisdropped) targetAttrs = lappend_int(targetAttrs, attnum); } } else if (operation == CMD_UPDATE) { int col; col = -1; while ((col = bms_next_member(rte->updatedCols, col)) >= 0) { /* bit numbers are offset by FirstLowInvalidHeapAttributeNumber */ AttrNumber attno = col + FirstLowInvalidHeapAttributeNumber; if (attno <= InvalidAttrNumber) /* shouldn't happen */ elog(ERROR, "system-column update is not supported"); targetAttrs = lappend_int(targetAttrs, attno); } } /* * Extract the relevant RETURNING list if any. */ if (plan->returningLists) returningList = (List *) list_nth(plan->returningLists, subplan_index); /* * ON CONFLICT DO UPDATE and DO NOTHING case with inference specification * should have already been rejected in the optimizer, as presently there * is no way to recognize an arbiter index on a foreign table. Only DO * NOTHING is supported without an inference specification. */ if (plan->onConflictAction == ONCONFLICT_NOTHING) doNothing = true; else if (plan->onConflictAction != ONCONFLICT_NONE) elog(ERROR, "unexpected ON CONFLICT specification: %d", (int) plan->onConflictAction); /* * Construct the SQL command string. */ switch (operation) { case CMD_INSERT: deparseInsertSql(&sql, root, resultRelation, rel, targetAttrs, doNothing, returningList, &retrieved_attrs); break; case CMD_UPDATE: deparseUpdateSql(&sql, root, resultRelation, rel, targetAttrs, returningList, &retrieved_attrs); break; case CMD_DELETE: deparseDeleteSql(&sql, root, resultRelation, rel, returningList, &retrieved_attrs); break; default: elog(ERROR, "unexpected operation: %d", (int) operation); break; } heap_close(rel, NoLock); /* * Build the fdw_private list that will be available to the executor. * Items in the list must match enum FdwModifyPrivateIndex, above. */ return list_make4(makeString(sql.data), targetAttrs, makeInteger((retrieved_attrs != NIL)), retrieved_attrs); } /* * treasuredataBeginForeignModify * Begin an insert/update/delete operation on a foreign table */ static void treasuredataBeginForeignModify(ModifyTableState *mtstate, ResultRelInfo *resultRelInfo, List *fdw_private, int subplan_index, int eflags) { TdFdwModifyState *fmstate; EState *estate = mtstate->ps.state; CmdType operation = mtstate->operation; Relation rel = resultRelInfo->ri_RelationDesc; RangeTblEntry *rte; Oid userid; ForeignTable *table; ForeignServer *server; UserMapping *user; AttrNumber n_params; Oid typefnoid; bool isvarlena; ListCell *lc; /* * Do nothing in EXPLAIN (no ANALYZE) case. resultRelInfo->ri_FdwState * stays NULL. */ if (eflags & EXEC_FLAG_EXPLAIN_ONLY) return; /* Begin constructing TdFdwModifyState. */ fmstate = (TdFdwModifyState *) palloc0(sizeof(TdFdwModifyState)); fmstate->rel = rel; /* * Identify which user to do the remote access as. This should match what * ExecCheckRTEPerms() does. */ rte = rt_fetch(resultRelInfo->ri_RangeTableIndex, estate->es_range_table); userid = rte->checkAsUser ? rte->checkAsUser : GetUserId(); /* Get info about foreign table. */ table = GetForeignTable(RelationGetRelid(rel)); server = GetForeignServer(table->serverid); user = GetUserMapping(userid, server->serverid); /* Open connection; report that we'll create a prepared statement. */ fmstate->conn = GetConnection(server, user, true); fmstate->p_name = NULL; /* prepared statement not made yet */ /* Deconstruct fdw_private data. */ fmstate->query = strVal(list_nth(fdw_private, FdwModifyPrivateUpdateSql)); fmstate->target_attrs = (List *) list_nth(fdw_private, FdwModifyPrivateTargetAttnums); fmstate->has_returning = intVal(list_nth(fdw_private, FdwModifyPrivateHasReturning)); fmstate->retrieved_attrs = (List *) list_nth(fdw_private, FdwModifyPrivateRetrievedAttrs); /* Create context for per-tuple temp workspace. */ fmstate->temp_cxt = AllocSetContextCreate(estate->es_query_cxt, "treasuredata_fdw temporary data", ALLOCSET_SMALL_MINSIZE, ALLOCSET_SMALL_INITSIZE, ALLOCSET_SMALL_MAXSIZE); /* Prepare for input conversion of RETURNING results. */ if (fmstate->has_returning) fmstate->attinmeta = TupleDescGetAttInMetadata(RelationGetDescr(rel)); /* Prepare for output conversion of parameters used in prepared stmt. */ n_params = list_length(fmstate->target_attrs) + 1; fmstate->p_flinfo = (FmgrInfo *) palloc0(sizeof(FmgrInfo) * n_params); fmstate->p_nums = 0; if (operation == CMD_UPDATE || operation == CMD_DELETE) { /* Find the ctid resjunk column in the subplan's result */ Plan *subplan = mtstate->mt_plans[subplan_index]->plan; fmstate->ctidAttno = ExecFindJunkAttributeInTlist(subplan->targetlist, "ctid"); if (!AttributeNumberIsValid(fmstate->ctidAttno)) elog(ERROR, "could not find junk ctid column"); /* First transmittable parameter will be ctid */ getTypeOutputInfo(TIDOID, &typefnoid, &isvarlena); fmgr_info(typefnoid, &fmstate->p_flinfo[fmstate->p_nums]); fmstate->p_nums++; } if (operation == CMD_INSERT || operation == CMD_UPDATE) { /* Set up for remaining transmittable parameters */ foreach(lc, fmstate->target_attrs) { int attnum = lfirst_int(lc); Form_pg_attribute attr = RelationGetDescr(rel)->attrs[attnum - 1]; Assert(!attr->attisdropped); getTypeOutputInfo(attr->atttypid, &typefnoid, &isvarlena); fmgr_info(typefnoid, &fmstate->p_flinfo[fmstate->p_nums]); fmstate->p_nums++; } } Assert(fmstate->p_nums <= n_params); resultRelInfo->ri_FdwState = fmstate; } /* * treasuredataExecForeignInsert * Insert one row into a foreign table */ static TupleTableSlot * treasuredataExecForeignInsert(EState *estate, ResultRelInfo *resultRelInfo, TupleTableSlot *slot, TupleTableSlot *planSlot) { TdFdwModifyState *fmstate = (TdFdwModifyState *) resultRelInfo->ri_FdwState; const char **p_values; PGresult *res; int n_rows; /* Set up the prepared statement on the remote server, if we didn't yet */ if (!fmstate->p_name) prepare_foreign_modify(fmstate); /* Convert parameters needed by prepared statement to text form */ p_values = convert_prep_stmt_params(fmstate, NULL, slot); /* * Execute the prepared statement, and check for success. * * We don't use a PG_TRY block here, so be careful not to throw error * without releasing the PGresult. */ res = PQexecPrepared(fmstate->conn, fmstate->p_name, fmstate->p_nums, p_values, NULL, NULL, 0); if (PQresultStatus(res) != (fmstate->has_returning ? PGRES_TUPLES_OK : PGRES_COMMAND_OK)) pgfdw_report_error(ERROR, res, fmstate->conn, true, fmstate->query); /* Check number of rows affected, and fetch RETURNING tuple if any */ if (fmstate->has_returning) { n_rows = PQntuples(res); if (n_rows > 0) store_returning_result(fmstate, slot, res); } else n_rows = atoi(PQcmdTuples(res)); /* And clean up */ PQclear(res); MemoryContextReset(fmstate->temp_cxt); /* Return NULL if nothing was inserted on the remote end */ return (n_rows > 0) ? slot : NULL; } /* * treasuredataExecForeignUpdate * Update one row in a foreign table */ static TupleTableSlot * treasuredataExecForeignUpdate(EState *estate, ResultRelInfo *resultRelInfo, TupleTableSlot *slot, TupleTableSlot *planSlot) { TdFdwModifyState *fmstate = (TdFdwModifyState *) resultRelInfo->ri_FdwState; Datum datum; bool isNull; const char **p_values; PGresult *res; int n_rows; /* Set up the prepared statement on the remote server, if we didn't yet */ if (!fmstate->p_name) prepare_foreign_modify(fmstate); /* Get the ctid that was passed up as a resjunk column */ datum = ExecGetJunkAttribute(planSlot, fmstate->ctidAttno, &isNull); /* shouldn't ever get a null result... */ if (isNull) elog(ERROR, "ctid is NULL"); /* Convert parameters needed by prepared statement to text form */ p_values = convert_prep_stmt_params(fmstate, (ItemPointer) DatumGetPointer(datum), slot); /* * Execute the prepared statement, and check for success. * * We don't use a PG_TRY block here, so be careful not to throw error * without releasing the PGresult. */ res = PQexecPrepared(fmstate->conn, fmstate->p_name, fmstate->p_nums, p_values, NULL, NULL, 0); if (PQresultStatus(res) != (fmstate->has_returning ? PGRES_TUPLES_OK : PGRES_COMMAND_OK)) pgfdw_report_error(ERROR, res, fmstate->conn, true, fmstate->query); /* Check number of rows affected, and fetch RETURNING tuple if any */ if (fmstate->has_returning) { n_rows = PQntuples(res); if (n_rows > 0) store_returning_result(fmstate, slot, res); } else n_rows = atoi(PQcmdTuples(res)); /* And clean up */ PQclear(res); MemoryContextReset(fmstate->temp_cxt); /* Return NULL if nothing was updated on the remote end */ return (n_rows > 0) ? slot : NULL; } /* * treasuredataExecForeignDelete * Delete one row from a foreign table */ static TupleTableSlot * treasuredataExecForeignDelete(EState *estate, ResultRelInfo *resultRelInfo, TupleTableSlot *slot, TupleTableSlot *planSlot) { TdFdwModifyState *fmstate = (TdFdwModifyState *) resultRelInfo->ri_FdwState; Datum datum; bool isNull; const char **p_values; PGresult *res; int n_rows; /* Set up the prepared statement on the remote server, if we didn't yet */ if (!fmstate->p_name) prepare_foreign_modify(fmstate); /* Get the ctid that was passed up as a resjunk column */ datum = ExecGetJunkAttribute(planSlot, fmstate->ctidAttno, &isNull); /* shouldn't ever get a null result... */ if (isNull) elog(ERROR, "ctid is NULL"); /* Convert parameters needed by prepared statement to text form */ p_values = convert_prep_stmt_params(fmstate, (ItemPointer) DatumGetPointer(datum), NULL); /* * Execute the prepared statement, and check for success. * * We don't use a PG_TRY block here, so be careful not to throw error * without releasing the PGresult. */ res = PQexecPrepared(fmstate->conn, fmstate->p_name, fmstate->p_nums, p_values, NULL, NULL, 0); if (PQresultStatus(res) != (fmstate->has_returning ? PGRES_TUPLES_OK : PGRES_COMMAND_OK)) pgfdw_report_error(ERROR, res, fmstate->conn, true, fmstate->query); /* Check number of rows affected, and fetch RETURNING tuple if any */ if (fmstate->has_returning) { n_rows = PQntuples(res); if (n_rows > 0) store_returning_result(fmstate, slot, res); } else n_rows = atoi(PQcmdTuples(res)); /* And clean up */ PQclear(res); MemoryContextReset(fmstate->temp_cxt); /* Return NULL if nothing was deleted on the remote end */ return (n_rows > 0) ? slot : NULL; } /* * treasuredataEndForeignModify * Finish an insert/update/delete operation on a foreign table */ static void treasuredataEndForeignModify(EState *estate, ResultRelInfo *resultRelInfo) { TdFdwModifyState *fmstate = (TdFdwModifyState *) resultRelInfo->ri_FdwState; /* If fmstate is NULL, we are in EXPLAIN; nothing to do */ if (fmstate == NULL) return; /* If we created a prepared statement, destroy it */ if (fmstate->p_name) { char sql[64]; PGresult *res; snprintf(sql, sizeof(sql), "DEALLOCATE %s", fmstate->p_name); /* * We don't use a PG_TRY block here, so be careful not to throw error * without releasing the PGresult. */ res = PQexec(fmstate->conn, sql); if (PQresultStatus(res) != PGRES_COMMAND_OK) pgfdw_report_error(ERROR, res, fmstate->conn, true, sql); PQclear(res); fmstate->p_name = NULL; } /* Release remote connection */ ReleaseConnection(fmstate->conn); fmstate->conn = NULL; } /* * treasuredataIsForeignRelUpdatable * Determine whether a foreign table supports INSERT, UPDATE and/or * DELETE. */ static int treasuredataIsForeignRelUpdatable(Relation rel) { bool updatable; ForeignTable *table; ForeignServer *server; ListCell *lc; /* * By default, all treasuredata_fdw foreign tables are assumed updatable. This * can be overridden by a per-server setting, which in turn can be * overridden by a per-table setting. */ updatable = true; table = GetForeignTable(RelationGetRelid(rel)); server = GetForeignServer(table->serverid); foreach(lc, server->options) { DefElem *def = (DefElem *) lfirst(lc); if (strcmp(def->defname, "updatable") == 0) updatable = defGetBoolean(def); } foreach(lc, table->options) { DefElem *def = (DefElem *) lfirst(lc); if (strcmp(def->defname, "updatable") == 0) updatable = defGetBoolean(def); } /* * Currently "updatable" means support for INSERT, UPDATE and DELETE. */ return updatable ? (1 << CMD_INSERT) | (1 << CMD_UPDATE) | (1 << CMD_DELETE) : 0; } /* * treasuredataExplainForeignScan * Produce extra output for EXPLAIN of a ForeignScan on a foreign table */ static void treasuredataExplainForeignScan(ForeignScanState *node, ExplainState *es) { List *fdw_private; char *sql; if (es->verbose) { fdw_private = ((ForeignScan *) node->ss.ps.plan)->fdw_private; sql = strVal(list_nth(fdw_private, FdwScanPrivateSelectSql)); ExplainPropertyText("Remote SQL", sql, es); } } /* * treasuredataExplainForeignModify * Produce extra output for EXPLAIN of a ModifyTable on a foreign table */ static void treasuredataExplainForeignModify(ModifyTableState *mtstate, ResultRelInfo *rinfo, List *fdw_private, int subplan_index, ExplainState *es) { if (es->verbose) { char *sql = strVal(list_nth(fdw_private, FdwModifyPrivateUpdateSql)); ExplainPropertyText("Remote SQL", sql, es); } } #endif /* * estimate_path_cost_size * Get cost and size estimates for a foreign scan * * We assume that all the baserestrictinfo clauses will be applied, plus * any join clauses listed in join_conds. */ static void estimate_path_cost_size(PlannerInfo *root, RelOptInfo *baserel, List *join_conds, double *p_rows, int *p_width, Cost *p_startup_cost, Cost *p_total_cost) { TdFdwRelationInfo *fpinfo = (TdFdwRelationInfo *) baserel->fdw_private; double rows; double retrieved_rows; int width; Cost startup_cost; Cost total_cost; Cost run_cost; Cost cpu_per_tuple; /* * We don't support join conditions in this mode (hence, no * parameterized paths can be made). */ Assert(join_conds == NIL); /* Use rows/width estimates made by set_baserel_size_estimates. */ rows = baserel->rows; #if PG_VERSION_NUM >= 90600 width = baserel->reltarget->width; #else width = baserel->width; #endif /* * Back into an estimate of the number of retrieved rows. Just in * case this is nuts, clamp to at most baserel->tuples. */ retrieved_rows = clamp_row_est(rows / fpinfo->local_conds_sel); retrieved_rows = Min(retrieved_rows, baserel->tuples); /* * Cost as though this were a seqscan, which is pessimistic. We * effectively imagine the local_conds are being evaluated remotely, * too. */ startup_cost = 0; run_cost = 0; run_cost += seq_page_cost * baserel->pages; startup_cost += baserel->baserestrictcost.startup; cpu_per_tuple = cpu_tuple_cost + baserel->baserestrictcost.per_tuple; run_cost += cpu_per_tuple * baserel->tuples; total_cost = startup_cost + run_cost; /* * Add some additional cost factors to account for connection overhead * (fdw_startup_cost), transferring data across the network * (fdw_tuple_cost per retrieved row), and local manipulation of the data * (cpu_tuple_cost per retrieved row). */ startup_cost += fpinfo->fdw_startup_cost; total_cost += fpinfo->fdw_startup_cost; total_cost += fpinfo->fdw_tuple_cost * retrieved_rows; total_cost += cpu_tuple_cost * retrieved_rows; /* Return results. */ *p_rows = rows; *p_width = width; *p_startup_cost = startup_cost; *p_total_cost = total_cost; } #if 0 /* * Detect whether we want to process an EquivalenceClass member. * * This is a callback for use by generate_implied_equalities_for_column. */ static bool ec_member_matches_foreign(PlannerInfo *root, RelOptInfo *rel, EquivalenceClass *ec, EquivalenceMember *em, void *arg) { ec_member_foreign_arg *state = (ec_member_foreign_arg *) arg; Expr *expr = em->em_expr; /* * If we've identified what we're processing in the current scan, we only * want to match that expression. */ if (state->current != NULL) return equal(expr, state->current); /* * Otherwise, ignore anything we've already processed. */ if (list_member(state->already_used, expr)) return false; /* This is the new target to process. */ state->current = expr; return true; } /* * Force assorted GUC parameters to settings that ensure that we'll output * data values in a form that is unambiguous to the remote server. * * This is rather expensive and annoying to do once per row, but there's * little choice if we want to be sure values are transmitted accurately; * we can't leave the settings in place between rows for fear of affecting * user-visible computations. * * We use the equivalent of a function SET option to allow the settings to * persist only until the caller calls reset_transmission_modes(). If an * error is thrown in between, guc.c will take care of undoing the settings. * * The return value is the nestlevel that must be passed to * reset_transmission_modes() to undo things. */ int set_transmission_modes(void) { int nestlevel = NewGUCNestLevel(); /* * The values set here should match what pg_dump does. See also * configure_remote_session in connection.c. */ if (DateStyle != USE_ISO_DATES) (void) set_config_option("datestyle", "ISO", PGC_USERSET, PGC_S_SESSION, GUC_ACTION_SAVE, true, 0, false); if (IntervalStyle != INTSTYLE_POSTGRES) (void) set_config_option("intervalstyle", "postgres", PGC_USERSET, PGC_S_SESSION, GUC_ACTION_SAVE, true, 0, false); if (extra_float_digits < 3) (void) set_config_option("extra_float_digits", "3", PGC_USERSET, PGC_S_SESSION, GUC_ACTION_SAVE, true, 0, false); return nestlevel; } /* * Undo the effects of set_transmission_modes(). */ void reset_transmission_modes(int nestlevel) { AtEOXact_GUC(true, nestlevel); } /* * prepare_foreign_modify * Establish a prepared statement for execution of INSERT/UPDATE/DELETE */ static void prepare_foreign_modify(TdFdwModifyState *fmstate) { char prep_name[NAMEDATALEN]; char *p_name; PGresult *res; /* Construct name we'll use for the prepared statement. */ snprintf(prep_name, sizeof(prep_name), "pgsql_fdw_prep_%u", GetPrepStmtNumber(fmstate->conn)); p_name = pstrdup(prep_name); /* * We intentionally do not specify parameter types here, but leave the * remote server to derive them by default. This avoids possible problems * with the remote server using different type OIDs than we do. All of * the prepared statements we use in this module are simple enough that * the remote server will make the right choices. * * We don't use a PG_TRY block here, so be careful not to throw error * without releasing the PGresult. */ res = PQprepare(fmstate->conn, p_name, fmstate->query, 0, NULL); if (PQresultStatus(res) != PGRES_COMMAND_OK) pgfdw_report_error(ERROR, res, fmstate->conn, true, fmstate->query); PQclear(res); /* This action shows that the prepare has been done. */ fmstate->p_name = p_name; } /* * convert_prep_stmt_params * Create array of text strings representing parameter values * * tupleid is ctid to send, or NULL if none * slot is slot to get remaining parameters from, or NULL if none * * Data is constructed in temp_cxt; caller should reset that after use. */ static const char ** convert_prep_stmt_params(TdFdwModifyState *fmstate, ItemPointer tupleid, TupleTableSlot *slot) { const char **p_values; int pindex = 0; MemoryContext oldcontext; oldcontext = MemoryContextSwitchTo(fmstate->temp_cxt); p_values = (const char **) palloc(sizeof(char *) * fmstate->p_nums); /* 1st parameter should be ctid, if it's in use */ if (tupleid != NULL) { /* don't need set_transmission_modes for TID output */ p_values[pindex] = OutputFunctionCall(&fmstate->p_flinfo[pindex], PointerGetDatum(tupleid)); pindex++; } /* get following parameters from slot */ if (slot != NULL && fmstate->target_attrs != NIL) { int nestlevel; ListCell *lc; nestlevel = set_transmission_modes(); foreach(lc, fmstate->target_attrs) { int attnum = lfirst_int(lc); Datum value; bool isnull; value = slot_getattr(slot, attnum, &isnull); if (isnull) p_values[pindex] = NULL; else p_values[pindex] = OutputFunctionCall(&fmstate->p_flinfo[pindex], value); pindex++; } reset_transmission_modes(nestlevel); } Assert(pindex == fmstate->p_nums); MemoryContextSwitchTo(oldcontext); return p_values; } /* * store_returning_result * Store the result of a RETURNING clause * * On error, be sure to release the PGresult on the way out. Callers do not * have PG_TRY blocks to ensure this happens. */ static void store_returning_result(TdFdwModifyState *fmstate, TupleTableSlot *slot, PGresult *res) { PG_TRY(); { HeapTuple newtup; newtup = make_tuple_from_result_row(res, 0, fmstate->rel, fmstate->attinmeta, fmstate->retrieved_attrs, fmstate->temp_cxt); /* tuple will be deleted when it is cleared from the slot */ ExecStoreTuple(newtup, slot, InvalidBuffer, true); } PG_CATCH(); { if (res) PQclear(res); PG_RE_THROW(); } PG_END_TRY(); } /* * treasuredataAnalyzeForeignTable * Test whether analyzing this foreign table is supported */ static bool treasuredataAnalyzeForeignTable(Relation relation, AcquireSampleRowsFunc *func, BlockNumber *totalpages) { ForeignTable *table; ForeignServer *server; UserMapping *user; PGconn *conn; StringInfoData sql; PGresult *volatile res = NULL; /* Return the row-analysis function pointer */ *func = treasuredataAcquireSampleRowsFunc; /* * Now we have to get the number of pages. It's annoying that the ANALYZE * API requires us to return that now, because it forces some duplication * of effort between this routine and treasuredataAcquireSampleRowsFunc. But * it's probably not worth redefining that API at this point. */ /* * Get the connection to use. We do the remote access as the table's * owner, even if the ANALYZE was started by some other user. */ table = GetForeignTable(RelationGetRelid(relation)); server = GetForeignServer(table->serverid); user = GetUserMapping(relation->rd_rel->relowner, server->serverid); conn = GetConnection(server, user, false); /* * Construct command to get page count for relation. */ initStringInfo(&sql); deparseAnalyzeSizeSql(&sql, relation); /* In what follows, do not risk leaking any PGresults. */ PG_TRY(); { res = PQexec(conn, sql.data); if (PQresultStatus(res) != PGRES_TUPLES_OK) pgfdw_report_error(ERROR, res, conn, false, sql.data); if (PQntuples(res) != 1 || PQnfields(res) != 1) elog(ERROR, "unexpected result from deparseAnalyzeSizeSql query"); *totalpages = strtoul(PQgetvalue(res, 0, 0), NULL, 10); PQclear(res); res = NULL; } PG_CATCH(); { if (res) PQclear(res); PG_RE_THROW(); } PG_END_TRY(); ReleaseConnection(conn); return true; } /* * Acquire a random sample of rows from foreign table managed by treasuredata_fdw. * * We fetch the whole table from the remote side and pick out some sample rows. * * Selected rows are returned in the caller-allocated array rows[], * which must have at least targrows entries. * The actual number of rows selected is returned as the function result. * We also count the total number of rows in the table and return it into * *totalrows. Note that *totaldeadrows is always set to 0. * * Note that the returned list of rows is not always in order by physical * position in the table. Therefore, correlation estimates derived later * may be meaningless, but it's OK because we don't use the estimates * currently (the planner only pays attention to correlation for indexscans). */ static int treasuredataAcquireSampleRowsFunc(Relation relation, int elevel, HeapTuple *rows, int targrows, double *totalrows, double *totaldeadrows) { TdFdwAnalyzeState astate; ForeignTable *table; ForeignServer *server; UserMapping *user; PGconn *conn; unsigned int cursor_number; StringInfoData sql; PGresult *volatile res = NULL; /* Initialize workspace state */ astate.rel = relation; astate.attinmeta = TupleDescGetAttInMetadata(RelationGetDescr(relation)); astate.rows = rows; astate.targrows = targrows; astate.numrows = 0; astate.samplerows = 0; astate.rowstoskip = -1; /* -1 means not set yet */ reservoir_init_selection_state(&astate.rstate, targrows); /* Remember ANALYZE context, and create a per-tuple temp context */ astate.anl_cxt = CurrentMemoryContext; astate.temp_cxt = AllocSetContextCreate(CurrentMemoryContext, "treasuredata_fdw temporary data", ALLOCSET_SMALL_MINSIZE, ALLOCSET_SMALL_INITSIZE, ALLOCSET_SMALL_MAXSIZE); /* * Get the connection to use. We do the remote access as the table's * owner, even if the ANALYZE was started by some other user. */ table = GetForeignTable(RelationGetRelid(relation)); server = GetForeignServer(table->serverid); user = GetUserMapping(relation->rd_rel->relowner, server->serverid); conn = GetConnection(server, user, false); /* * Construct cursor that retrieves whole rows from remote. */ cursor_number = GetCursorNumber(conn); initStringInfo(&sql); appendStringInfo(&sql, "DECLARE c%u CURSOR FOR ", cursor_number); deparseAnalyzeSql(&sql, relation, &astate.retrieved_attrs); /* In what follows, do not risk leaking any PGresults. */ PG_TRY(); { res = PQexec(conn, sql.data); if (PQresultStatus(res) != PGRES_COMMAND_OK) pgfdw_report_error(ERROR, res, conn, false, sql.data); PQclear(res); res = NULL; /* Retrieve and process rows a batch at a time. */ for (;;) { char fetch_sql[64]; int fetch_size; int numrows; int i; /* Allow users to cancel long query */ CHECK_FOR_INTERRUPTS(); /* * XXX possible future improvement: if rowstoskip is large, we * could issue a MOVE rather than physically fetching the rows, * then just adjust rowstoskip and samplerows appropriately. */ /* The fetch size is arbitrary, but shouldn't be enormous. */ fetch_size = 100; /* Fetch some rows */ snprintf(fetch_sql, sizeof(fetch_sql), "FETCH %d FROM c%u", fetch_size, cursor_number); res = PQexec(conn, fetch_sql); /* On error, report the original query, not the FETCH. */ if (PQresultStatus(res) != PGRES_TUPLES_OK) pgfdw_report_error(ERROR, res, conn, false, sql.data); /* Process whatever we got. */ numrows = PQntuples(res); for (i = 0; i < numrows; i++) analyze_row_processor(res, i, &astate); PQclear(res); res = NULL; /* Must be EOF if we didn't get all the rows requested. */ if (numrows < fetch_size) break; } /* Close the cursor, just to be tidy. */ close_cursor(conn, cursor_number); } PG_CATCH(); { if (res) PQclear(res); PG_RE_THROW(); } PG_END_TRY(); ReleaseConnection(conn); /* We assume that we have no dead tuple. */ *totaldeadrows = 0.0; /* We've retrieved all living tuples from foreign server. */ *totalrows = astate.samplerows; /* * Emit some interesting relation info */ ereport(elevel, (errmsg("\"%s\": table contains %.0f rows, %d rows in sample", RelationGetRelationName(relation), astate.samplerows, astate.numrows))); return astate.numrows; } /* * Collect sample rows from the result of query. * - Use all tuples in sample until target # of samples are collected. * - Subsequently, replace already-sampled tuples randomly. */ static void analyze_row_processor(PGresult *res, int row, TdFdwAnalyzeState *astate) { int targrows = astate->targrows; int pos; /* array index to store tuple in */ MemoryContext oldcontext; /* Always increment sample row counter. */ astate->samplerows += 1; /* * Determine the slot where this sample row should be stored. Set pos to * negative value to indicate the row should be skipped. */ if (astate->numrows < targrows) { /* First targrows rows are always included into the sample */ pos = astate->numrows++; } else { /* * Now we start replacing tuples in the sample until we reach the end * of the relation. Same algorithm as in acquire_sample_rows in * analyze.c; see Jeff Vitter's paper. */ if (astate->rowstoskip < 0) astate->rowstoskip = reservoir_get_next_S(&astate->rstate, astate->samplerows, targrows); if (astate->rowstoskip <= 0) { /* Choose a random reservoir element to replace. */ pos = (int) (targrows * sampler_random_fract(astate->rstate.randstate)); Assert(pos >= 0 && pos < targrows); heap_freetuple(astate->rows[pos]); } else { /* Skip this tuple. */ pos = -1; } astate->rowstoskip -= 1; } if (pos >= 0) { /* * Create sample tuple from current result row, and store it in the * position determined above. The tuple has to be created in anl_cxt. */ oldcontext = MemoryContextSwitchTo(astate->anl_cxt); astate->rows[pos] = make_tuple_from_result_row(res, row, astate->rel, astate->attinmeta, astate->retrieved_attrs, astate->temp_cxt); MemoryContextSwitchTo(oldcontext); } } /* * Import a foreign schema */ static List * treasuredataImportForeignSchema(ImportForeignSchemaStmt *stmt, Oid serverOid) { List *commands = NIL; bool import_collate = true; bool import_default = false; bool import_not_null = true; ForeignServer *server; UserMapping *mapping; PGconn *conn; StringInfoData buf; PGresult *volatile res = NULL; int numrows, i; ListCell *lc; /* Parse statement options */ foreach(lc, stmt->options) { DefElem *def = (DefElem *) lfirst(lc); if (strcmp(def->defname, "import_collate") == 0) import_collate = defGetBoolean(def); else if (strcmp(def->defname, "import_default") == 0) import_default = defGetBoolean(def); else if (strcmp(def->defname, "import_not_null") == 0) import_not_null = defGetBoolean(def); else ereport(ERROR, (errcode(ERRCODE_FDW_INVALID_OPTION_NAME), errmsg("invalid option \"%s\"", def->defname))); } /* * Get connection to the foreign server. Connection manager will * establish new connection if necessary. */ server = GetForeignServer(serverOid); mapping = GetUserMapping(GetUserId(), server->serverid); conn = GetConnection(server, mapping, false); /* Don't attempt to import collation if remote server hasn't got it */ if (PQserverVersion(conn) < 90100) import_collate = false; /* Create workspace for strings */ initStringInfo(&buf); /* In what follows, do not risk leaking any PGresults. */ PG_TRY(); { /* Check that the schema really exists */ appendStringInfoString(&buf, "SELECT 1 FROM pg_catalog.pg_namespace WHERE nspname = "); deparseStringLiteral(&buf, stmt->remote_schema); res = PQexec(conn, buf.data); if (PQresultStatus(res) != PGRES_TUPLES_OK) pgfdw_report_error(ERROR, res, conn, false, buf.data); if (PQntuples(res) != 1) ereport(ERROR, (errcode(ERRCODE_FDW_SCHEMA_NOT_FOUND), errmsg("schema \"%s\" is not present on foreign server \"%s\"", stmt->remote_schema, server->servername))); PQclear(res); res = NULL; resetStringInfo(&buf); /* * Fetch all table data from this schema, possibly restricted by * EXCEPT or LIMIT TO. (We don't actually need to pay any attention * to EXCEPT/LIMIT TO here, because the core code will filter the * statements we return according to those lists anyway. But it * should save a few cycles to not process excluded tables in the * first place.) * * Note: because we run the connection with search_path restricted to * pg_catalog, the format_type() and pg_get_expr() outputs will always * include a schema name for types/functions in other schemas, which * is what we want. */ if (import_collate) appendStringInfoString(&buf, "SELECT relname, " " attname, " " format_type(atttypid, atttypmod), " " attnotnull, " " pg_get_expr(adbin, adrelid), " " collname, " " collnsp.nspname " "FROM pg_class c " " JOIN pg_namespace n ON " " relnamespace = n.oid " " LEFT JOIN pg_attribute a ON " " attrelid = c.oid AND attnum > 0 " " AND NOT attisdropped " " LEFT JOIN pg_attrdef ad ON " " adrelid = c.oid AND adnum = attnum " " LEFT JOIN pg_collation coll ON " " coll.oid = attcollation " " LEFT JOIN pg_namespace collnsp ON " " collnsp.oid = collnamespace "); else appendStringInfoString(&buf, "SELECT relname, " " attname, " " format_type(atttypid, atttypmod), " " attnotnull, " " pg_get_expr(adbin, adrelid), " " NULL, NULL " "FROM pg_class c " " JOIN pg_namespace n ON " " relnamespace = n.oid " " LEFT JOIN pg_attribute a ON " " attrelid = c.oid AND attnum > 0 " " AND NOT attisdropped " " LEFT JOIN pg_attrdef ad ON " " adrelid = c.oid AND adnum = attnum "); appendStringInfoString(&buf, "WHERE c.relkind IN ('r', 'v', 'f', 'm') " " AND n.nspname = "); deparseStringLiteral(&buf, stmt->remote_schema); /* Apply restrictions for LIMIT TO and EXCEPT */ if (stmt->list_type == FDW_IMPORT_SCHEMA_LIMIT_TO || stmt->list_type == FDW_IMPORT_SCHEMA_EXCEPT) { bool first_item = true; appendStringInfoString(&buf, " AND c.relname "); if (stmt->list_type == FDW_IMPORT_SCHEMA_EXCEPT) appendStringInfoString(&buf, "NOT "); appendStringInfoString(&buf, "IN ("); /* Append list of table names within IN clause */ foreach(lc, stmt->table_list) { RangeVar *rv = (RangeVar *) lfirst(lc); if (first_item) first_item = false; else appendStringInfoString(&buf, ", "); deparseStringLiteral(&buf, rv->relname); } appendStringInfoChar(&buf, ')'); } /* Append ORDER BY at the end of query to ensure output ordering */ appendStringInfoString(&buf, " ORDER BY c.relname, a.attnum"); /* Fetch the data */ res = PQexec(conn, buf.data); if (PQresultStatus(res) != PGRES_TUPLES_OK) pgfdw_report_error(ERROR, res, conn, false, buf.data); /* Process results */ numrows = PQntuples(res); /* note: incrementation of i happens in inner loop's while() test */ for (i = 0; i < numrows;) { char *tablename = PQgetvalue(res, i, 0); bool first_item = true; resetStringInfo(&buf); appendStringInfo(&buf, "CREATE FOREIGN TABLE %s (\n", quote_identifier(tablename)); /* Scan all rows for this table */ do { char *attname; char *typename; char *attnotnull; char *attdefault; char *collname; char *collnamespace; /* If table has no columns, we'll see nulls here */ if (PQgetisnull(res, i, 1)) continue; attname = PQgetvalue(res, i, 1); typename = PQgetvalue(res, i, 2); attnotnull = PQgetvalue(res, i, 3); attdefault = PQgetisnull(res, i, 4) ? (char *) NULL : PQgetvalue(res, i, 4); collname = PQgetisnull(res, i, 5) ? (char *) NULL : PQgetvalue(res, i, 5); collnamespace = PQgetisnull(res, i, 6) ? (char *) NULL : PQgetvalue(res, i, 6); if (first_item) first_item = false; else appendStringInfoString(&buf, ",\n"); /* Print column name and type */ appendStringInfo(&buf, " %s %s", quote_identifier(attname), typename); /* * Add column_name option so that renaming the foreign table's * column doesn't break the association to the underlying * column. */ appendStringInfoString(&buf, " OPTIONS (column_name "); deparseStringLiteral(&buf, attname); appendStringInfoChar(&buf, ')'); /* Add COLLATE if needed */ if (import_collate && collname != NULL && collnamespace != NULL) appendStringInfo(&buf, " COLLATE %s.%s", quote_identifier(collnamespace), quote_identifier(collname)); /* Add DEFAULT if needed */ if (import_default && attdefault != NULL) appendStringInfo(&buf, " DEFAULT %s", attdefault); /* Add NOT NULL if needed */ if (import_not_null && attnotnull[0] == 't') appendStringInfoString(&buf, " NOT NULL"); } while (++i < numrows && strcmp(PQgetvalue(res, i, 0), tablename) == 0); /* * Add server name and table-level options. We specify remote * schema and table name as options (the latter to ensure that * renaming the foreign table doesn't break the association). */ appendStringInfo(&buf, "\n) SERVER %s\nOPTIONS (", quote_identifier(server->servername)); appendStringInfoString(&buf, "schema_name "); deparseStringLiteral(&buf, stmt->remote_schema); appendStringInfoString(&buf, ", table_name "); deparseStringLiteral(&buf, tablename); appendStringInfoString(&buf, ");"); commands = lappend(commands, pstrdup(buf.data)); } /* Clean up */ PQclear(res); res = NULL; } PG_CATCH(); { if (res) PQclear(res); PG_RE_THROW(); } PG_END_TRY(); ReleaseConnection(conn); return commands; } #endif /* * Create a tuple from the specified row of the PGresult. * * rel is the local representation of the foreign table, attinmeta is * conversion data for the rel's tupdesc, and retrieved_attrs is an * integer list of the table column numbers present in the PGresult. * temp_context is a working context that can be reset after each tuple. */ static HeapTuple make_tuple_from_result_row(void *td_client, Relation rel, AttInMetadata *attinmeta, List *retrieved_attrs, MemoryContext temp_context) { HeapTuple tuple; TupleDesc tupdesc = RelationGetDescr(rel); Datum *values; char **result_values; bool *nulls; ItemPointer ctid = NULL; ConversionLocation errpos; ErrorContextCallback errcallback; MemoryContext oldcontext; ListCell *lc; int j; // Assert(row < PQntuples(res)); /* * Do the following work in a temp context that we reset after each tuple. * This cleans up not only the data we have direct access to, but any * cruft the I/O functions might leak. */ oldcontext = MemoryContextSwitchTo(temp_context); values = (Datum *) palloc0(tupdesc->natts * sizeof(Datum)); result_values = (char **) palloc0(tupdesc->natts * sizeof(char *)); nulls = (bool *) palloc(tupdesc->natts * sizeof(bool)); /* Initialize to nulls for any columns not present in result */ memset(nulls, true, tupdesc->natts * sizeof(bool)); /* * Set up and install callback to report where conversion error occurs. */ errpos.rel = rel; errpos.cur_attno = 0; errcallback.callback = conversion_error_callback; errcallback.arg = (void *) &errpos; errcallback.previous = error_context_stack; error_context_stack = &errcallback; if (fetchResultRow(td_client, tupdesc->natts, result_values) != 0) { error_context_stack = errcallback.previous; MemoryContextSwitchTo(oldcontext); MemoryContextReset(temp_context); return NULL; } /* * i indexes columns in the relation, j indexes columns in the PGresult. */ j = 0; foreach(lc, retrieved_attrs) { int i = lfirst_int(lc); char *valstr; valstr = result_values[j]; /* convert value to internal representation */ if (i > 0) { /* ordinary column */ Assert(i <= tupdesc->natts); nulls[i - 1] = (valstr == NULL); /* Apply the input function even to nulls, to support domains */ errpos.cur_attno = i; values[i - 1] = InputFunctionCall(&attinmeta->attinfuncs[i - 1], valstr, attinmeta->attioparams[i - 1], attinmeta->atttypmods[i - 1]); errpos.cur_attno = 0; } else if (i == SelfItemPointerAttributeNumber) { /* ctid --- note we ignore any other system column in result */ if (valstr != NULL) { Datum datum; datum = DirectFunctionCall1(tidin, CStringGetDatum(valstr)); ctid = (ItemPointer) DatumGetPointer(datum); } } j++; } /* Uninstall error context callback. */ error_context_stack = errcallback.previous; /* * Build the result tuple in caller's memory context. */ MemoryContextSwitchTo(oldcontext); tuple = heap_form_tuple(tupdesc, values, nulls); /* * If we have a CTID to return, install it in both t_self and t_ctid. * t_self is the normal place, but if the tuple is converted to a * composite Datum, t_self will be lost; setting t_ctid allows CTID to be * preserved during EvalPlanQual re-evaluations (see ROW_MARK_COPY code). */ if (ctid) tuple->t_self = tuple->t_data->t_ctid = *ctid; /* Clean up */ MemoryContextReset(temp_context); return tuple; } /* * Callback function which is called when error occurs during column value * conversion. Print names of column and relation. */ static void conversion_error_callback(void *arg) { ConversionLocation *errpos = (ConversionLocation *) arg; TupleDesc tupdesc = RelationGetDescr(errpos->rel); if (errpos->cur_attno > 0 && errpos->cur_attno <= tupdesc->natts) errcontext("column \"%s\" of foreign table \"%s\"", NameStr(tupdesc->attrs[errpos->cur_attno - 1]->attname), RelationGetRelationName(errpos->rel)); }