/* ------------------------------------------------------------------------- * * rewriteHandler.cpp * Primary module of query rewriter. * * Portions Copyright (c) 2020 Huawei Technologies Co.,Ltd. * Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION * src/gausskernel/optimizer/rewrite/rewriteHandler.cpp * * ------------------------------------------------------------------------- */ #include "postgres.h" #include "knl/knl_variable.h" #include "access/sysattr.h" #include "catalog/gs_matview_dependency.h" #include "catalog/gs_matview.h" #include "catalog/pg_type.h" #include "catalog/pg_class.h" #include "catalog/pg_proc.h" #include "commands/trigger.h" #include "commands/matview.h" #include "commands/sequence.h" #include "commands/tablecmds.h" #include "executor/executor.h" #include "foreign/fdwapi.h" #include "nodes/makefuncs.h" #include "nodes/nodeFuncs.h" #include "parser/analyze.h" #include "parser/parse_coerce.h" #include "parser/parsetree.h" #include "parser/parse_merge.h" #include "rewrite/rewriteDefine.h" #include "rewrite/rewriteHandler.h" #include "rewrite/rewriteManip.h" #include "rewrite/rewriteRlsPolicy.h" #include "utils/builtins.h" #include "utils/lsyscache.h" #include "utils/rel.h" #include "utils/rel_gs.h" #include "catalog/pg_constraint.h" #include "catalog/namespace.h" #include "client_logic/client_logic.h" #include "catalog/pg_proc.h" #include "commands/sqladvisor.h" #ifdef PGXC #include "pgxc/locator.h" #include "pgxc/nodemgr.h" #include "pgxc/pgxc.h" #include "nodes/nodes.h" #include "optimizer/planner.h" #include "optimizer/var.h" #include "tcop/tcopprot.h" #include "tcop/utility.h" #ifdef ENABLE_MULTIPLE_NODES #include "tsdb/utils/ts_redis.h" #endif #endif /* We use a list of these to detect recursion in RewriteQuery */ typedef struct rewrite_event { Oid relation; /* OID of relation having rules */ CmdType event; /* type of rule being fired */ } rewrite_event; static bool acquireLocksOnSubLinks(Node* node, void* context); static Query* rewriteRuleAction( Query* parsetree, Query* rule_action, Node* rule_qual, int rt_index, CmdType event, bool* returning_flag); static List* adjustJoinTreeList(Query* parsetree, bool removert, int rt_index); static List *rewriteTargetListIU(List *targetList, CmdType commandType, Relation target_relation, int result_rtindex, List **attrno_list, bool *hasGenCol); static TargetEntry* process_matched_tle(TargetEntry* src_tle, TargetEntry* prior_tle, const char* attrName); static Node* get_assignment_input(Node* node); static void rewriteValuesRTE(RangeTblEntry* rte, Relation target_relation, List* attrnos); static void rewriteTargetListUD(Query* parsetree, RangeTblEntry* target_rte, Relation target_relation, int rtindex); static void rewriteTargetListMutilUD(Query* parsetree, List* rtable, List* resultRelations); static void rewriteTargetListMutilUpdate(Query* parsetree, List* rtable, List* resultRelations); static void markQueryForLocking(Query* qry, Node* jtnode, LockClauseStrength strength, LockWaitPolicy waitPolicy, bool pushedDown, int waitSec); static List* matchLocks(CmdType event, RuleLock* rulelocks, int varno, Query* parsetree); static Query* fireRIRrules(Query* parsetree, List* activeRIRs, bool forUpdatePushedDown); #ifdef PGXC typedef struct pull_qual_vars_context { List* varlist; int sublevels_up; int resultRelation; bool noRepeat; } pull_qual_vars_context; static bool pull_qual_vars_walker(Node* node, pull_qual_vars_context* context); #endif /* * AcquireRewriteLocks - * Acquire suitable locks on all the relations mentioned in the Query. * These locks will ensure that the relation schemas don't change under us * while we are rewriting and planning the query. * * forUpdatePushedDown indicates that a pushed-down FOR UPDATE/SHARE applies * to the current subquery, requiring all rels to be opened with RowShareLock. * This should always be false at the start of the recursion. * * Caution: A secondary purpose of this routine is to fix up JOIN RTE references * to dropped columns (see details below). Because the RTEs are modified in * place, it is generally appropriate for the caller of this routine to have * first done a copyObject() to make a writable copy of the querytree in the * current memory context. * * This processing can, and for efficiency's sake should, be skipped when the * querytree has just been built by the parser: parse analysis already got * all the same locks we'd get here, and the parser will have omitted dropped * columns from JOINs to begin with. But we must do this whenever we are * dealing with a querytree produced earlier than the current command. * * About JOINs and dropped columns: although the parser never includes an * already-dropped column in a JOIN RTE's alias var list, it is possible for * such a list in a stored rule to include references to dropped columns. * (If the column is not explicitly referenced anywhere else in the query, * the dependency mechanism won't consider it used by the rule and so won't * prevent the column drop.) To support get_rte_attribute_is_dropped(), * we replace join alias vars that reference dropped columns with NULL Const * nodes. * * (In PostgreSQL 8.0, we did not do this processing but instead had * get_rte_attribute_is_dropped() recurse to detect dropped columns in joins. * That approach had horrible performance unfortunately; in particular * construction of a nested join was O(N^2) in the nesting depth.) */ void AcquireRewriteLocks(Query* parsetree, bool forUpdatePushedDown) { ListCell* l = NULL; int rt_index; /* * First, process RTEs of the current query level. */ rt_index = 0; foreach (l, parsetree->rtable) { RangeTblEntry* rte = (RangeTblEntry*)lfirst(l); Relation rel; LOCKMODE lockmode; List* newaliasvars = NIL; Index curinputvarno; RangeTblEntry* curinputrte = NULL; ListCell* ll = NULL; ++rt_index; switch (rte->rtekind) { case RTE_RELATION: /* * Grab the appropriate lock type for the relation, and do not * release it until end of transaction. This protects the * rewriter and planner against schema changes mid-query. * * If the relation is the query's result relation, then we * need RowExclusiveLock. Otherwise, check to see if the * relation is accessed FOR [KEY] UPDATE/SHARE or not. We can't * just grab AccessShareLock because then the executor would * be trying to upgrade the lock, leading to possible * deadlocks. */ if (rt_index == linitial2_int(parsetree->resultRelations)) lockmode = RowExclusiveLock; else if (forUpdatePushedDown || get_parse_rowmark(parsetree, rt_index) != NULL) lockmode = RowShareLock; else lockmode = AccessShareLock; rel = heap_open(rte->relid, lockmode); /* * While we have the relation open, update the RTE's relkind, * just in case it changed since this rule was made. */ rte->relkind = rel->rd_rel->relkind; heap_close(rel, NoLock); break; case RTE_JOIN: /* * Scan the join's alias var list to see if any columns have * been dropped, and if so replace those Vars with NULL * Consts. * * Since a join has only two inputs, we can expect to see * multiple references to the same input RTE; optimize away * multiple fetches. */ newaliasvars = NIL; curinputvarno = 0; curinputrte = NULL; foreach (ll, rte->joinaliasvars) { Var* aliasvar = (Var*)lfirst(ll); /* * If the list item isn't a simple Var, then it must * represent a merged column, ie a USING column, and so it * couldn't possibly be dropped, since it's referenced in * the join clause. (Conceivably it could also be a NULL * constant already? But that's OK too.) */ if (IsA(aliasvar, Var)) { /* * The elements of an alias list have to refer to * earlier RTEs of the same rtable, because that's the * order the planner builds things in. So we already * processed the referenced RTE, and so it's safe to * use get_rte_attribute_is_dropped on it. (This might * not hold after rewriting or planning, but it's OK * to assume here.) */ AssertEreport(aliasvar->varlevelsup == 0, MOD_OPT, ""); if (aliasvar->varno != curinputvarno) { curinputvarno = aliasvar->varno; curinputrte = rt_fetch(curinputvarno, parsetree->rtable); } if (curinputrte != NULL && get_rte_attribute_is_dropped(curinputrte, aliasvar->varattno)) { /* * can't use vartype here, since that might be a * now-dropped type OID, but it doesn't really * matter what type the Const claims to be. */ aliasvar = (Var*)makeNullConst(INT4OID, -1, InvalidOid); } } newaliasvars = lappend(newaliasvars, aliasvar); } rte->joinaliasvars = newaliasvars; break; case RTE_SUBQUERY: /* * The subquery RTE itself is all right, but we have to * recurse to process the represented subquery. */ AcquireRewriteLocks( rte->subquery, (forUpdatePushedDown || get_parse_rowmark(parsetree, rt_index) != NULL)); break; default: /* ignore other types of RTEs */ break; } } /* Recurse into subqueries in WITH */ foreach (l, parsetree->cteList) { CommonTableExpr* cte = (CommonTableExpr*)lfirst(l); AcquireRewriteLocks((Query*)cte->ctequery, false); } /* * Recurse into sublink subqueries, too. But we already did the ones in * the rtable and cteList. */ if (parsetree->hasSubLinks) (void)query_tree_walker(parsetree, (bool (*)())acquireLocksOnSubLinks, NULL, QTW_IGNORE_RC_SUBQUERIES); } /* * Walker to find sublink subqueries for AcquireRewriteLocks */ static bool acquireLocksOnSubLinks(Node* node, void* context) { if (node == NULL) return false; if (IsA(node, SubLink)) { SubLink* sub = (SubLink*)node; /* Do what we came for */ AcquireRewriteLocks((Query*)sub->subselect, false); /* Fall through to process lefthand args of SubLink */ } /* * Do NOT recurse into Query nodes, because AcquireRewriteLocks already * processed subselects of subselects for us. */ return expression_tree_walker(node, (bool (*)())acquireLocksOnSubLinks, context); } /* * rewriteRuleAction - * Rewrite the rule action with appropriate qualifiers (taken from * the triggering query). * * Input arguments: * parsetree - original query * rule_action - one action (query) of a rule * rule_qual - WHERE condition of rule, or NULL if unconditional * rt_index - RT index of result relation in original query * event - type of rule event * Output arguments: * *returning_flag - set TRUE if we rewrite RETURNING clause in rule_action * (must be initialized to FALSE) * Return value: * rewritten form of rule_action */ static Query* rewriteRuleAction( Query* parsetree, Query* rule_action, Node* rule_qual, int rt_index, CmdType event, bool* returning_flag) { int current_varno, new_varno; int rt_length; Query* sub_action = NULL; Query** sub_action_ptr; /* * Make modifiable copies of rule action and qual (what we're passed are * the stored versions in the relcache; don't touch 'em!). */ rule_action = (Query*)copyObject(rule_action); rule_qual = (Node*)copyObject(rule_qual); /* * Acquire necessary locks and fix any deleted JOIN RTE entries. */ AcquireRewriteLocks(rule_action, false); (void)acquireLocksOnSubLinks(rule_qual, NULL); current_varno = rt_index; rt_length = list_length(parsetree->rtable); new_varno = PRS2_NEW_VARNO + rt_length; /* * Adjust rule action and qual to offset its varnos, so that we can merge * its rtable with the main parsetree's rtable. * * If the rule action is an INSERT...SELECT, the OLD/NEW rtable entries * will be in the SELECT part, and we have to modify that rather than the * top-level INSERT (kluge!). */ sub_action = getInsertSelectQuery(rule_action, &sub_action_ptr); OffsetVarNodes((Node*)sub_action, rt_length, 0); OffsetVarNodes(rule_qual, rt_length, 0); /* but references to OLD should point at original rt_index */ ChangeVarNodes((Node*)sub_action, PRS2_OLD_VARNO + rt_length, rt_index, 0); ChangeVarNodes(rule_qual, PRS2_OLD_VARNO + rt_length, rt_index, 0); /* * Generate expanded rtable consisting of main parsetree's rtable plus * rule action's rtable; this becomes the complete rtable for the rule * action. Some of the entries may be unused after we finish rewriting, * but we leave them all in place for two reasons: * * We'd have a much harder job to adjust the query's varnos if we * selectively removed RT entries. * * If the rule is INSTEAD, then the original query won't be executed at * all, and so its rtable must be preserved so that the executor will do * the correct permissions checks on it. * * RT entries that are not referenced in the completed jointree will be * ignored by the planner, so they do not affect query semantics. But any * permissions checks specified in them will be applied during executor * startup (see ExecCheckRTEPerms()). This allows us to check that the * caller has, say, insert-permission on a view, when the view is not * semantically referenced at all in the resulting query. * * When a rule is not INSTEAD, the permissions checks done on its copied * RT entries will be redundant with those done during execution of the * original query, but we don't bother to treat that case differently. * * NOTE: because planner will destructively alter rtable, we must ensure * that rule action's rtable is separate and shares no substructure with * the main rtable. Hence do a deep copy here. */ sub_action->rtable = list_concat((List*)copyObject(parsetree->rtable), sub_action->rtable); /* * There could have been some SubLinks in parsetree's rtable, in which * case we'd better mark the sub_action correctly. */ if (parsetree->hasSubLinks && !sub_action->hasSubLinks) { ListCell* lc = NULL; foreach (lc, parsetree->rtable) { RangeTblEntry* rte = (RangeTblEntry*)lfirst(lc); switch (rte->rtekind) { case RTE_RELATION: sub_action->hasSubLinks = checkExprHasSubLink((Node*)rte->tablesample) || checkExprHasSubLink((Node*)rte->timecapsule); break; case RTE_FUNCTION: sub_action->hasSubLinks = checkExprHasSubLink(rte->funcexpr); break; case RTE_VALUES: sub_action->hasSubLinks = checkExprHasSubLink((Node*)rte->values_lists); break; default: /* other RTE types don't contain bare expressions */ break; } if (sub_action->hasSubLinks) break; /* no need to keep scanning rtable */ } } /* * Also, we might have absorbed some RTEs with RLS conditions into the * sub_action. If so, mark it as hasRowSecurity, whether or not those * RTEs will be referenced after we finish rewriting. (Note: currently * this is a no-op because RLS conditions aren't added till later, but it * seems like good future-proofing to do this anyway.) */ sub_action->hasRowSecurity = (sub_action->hasRowSecurity || parsetree->hasRowSecurity); /* * Each rule action's jointree should be the main parsetree's jointree * plus that rule's jointree, but usually *without* the original rtindex * that we're replacing (if present, which it won't be for INSERT). Note * that if the rule action refers to OLD, its jointree will add a * reference to rt_index. If the rule action doesn't refer to OLD, but * either the rule_qual or the user query quals do, then we need to keep * the original rtindex in the jointree to provide data for the quals. We * don't want the original rtindex to be joined twice, however, so avoid * keeping it if the rule action mentions it. * * As above, the action's jointree must not share substructure with the * main parsetree's. */ if (sub_action->commandType != CMD_UTILITY) { bool keeporig = false; List* newjointree = NIL; AssertEreport(sub_action->jointree != NULL, MOD_OPT, ""); keeporig = (!rangeTableEntry_used((Node*)sub_action->jointree, rt_index, 0)) && (rangeTableEntry_used(rule_qual, rt_index, 0) || rangeTableEntry_used(parsetree->jointree->quals, rt_index, 0)); newjointree = adjustJoinTreeList(parsetree, !keeporig, rt_index); if (newjointree != NIL) { /* * If sub_action is a setop, manipulating its jointree will do no * good at all, because the jointree is dummy. (Perhaps someday * we could push the joining and quals down to the member * statements of the setop?) */ if (sub_action->setOperations != NULL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("conditional UNION/INTERSECT/EXCEPT statements are not implemented"))); sub_action->jointree->fromlist = list_concat(newjointree, sub_action->jointree->fromlist); /* * There could have been some SubLinks in newjointree, in which * case we'd better mark the sub_action correctly. */ if (parsetree->hasSubLinks && !sub_action->hasSubLinks) sub_action->hasSubLinks = checkExprHasSubLink((Node*)newjointree); } } /* * If the original query has any CTEs, copy them into the rule action. But * we don't need them for a utility action. */ if (parsetree->cteList != NIL && sub_action->commandType != CMD_UTILITY) { ListCell* lc = NULL; /* * Annoying implementation restriction: because CTEs are identified by * name within a cteList, we can't merge a CTE from the original query * if it has the same name as any CTE in the rule action. * * This could possibly be fixed by using some sort of internally * generated ID, instead of names, to link CTE RTEs to their CTEs. */ foreach (lc, parsetree->cteList) { CommonTableExpr* cte = (CommonTableExpr*)lfirst(lc); ListCell* lc2 = NULL; foreach (lc2, sub_action->cteList) { CommonTableExpr* cte2 = (CommonTableExpr*)lfirst(lc2); if (strcmp(cte->ctename, cte2->ctename) == 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("WITH query name \"%s\" appears in both a rule action and the query being rewritten", cte->ctename))); } } /* OK, it's safe to combine the CTE lists */ sub_action->cteList = list_concat(sub_action->cteList, (List*)copyObject(parsetree->cteList)); } /* * Event Qualification forces copying of parsetree and splitting into two * queries one w/rule_qual, one w/NOT rule_qual. Also add user query qual * onto rule action */ AddQual(sub_action, rule_qual); AddQual(sub_action, parsetree->jointree->quals); /* * Rewrite new.attribute w/ right hand side of target-list entry for * appropriate field name in insert/update. * * KLUGE ALERT: since ResolveNew returns a mutated copy, we can't just * apply it to sub_action; we have to remember to update the sublink * inside rule_action, too. */ if ((event == CMD_INSERT || event == CMD_UPDATE) && sub_action->commandType != CMD_UTILITY) { sub_action = (Query*)ResolveNew((Node*)sub_action, new_varno, 0, rt_fetch(new_varno, sub_action->rtable), parsetree->targetList, event, current_varno, NULL); if (sub_action_ptr != NULL) *sub_action_ptr = sub_action; else rule_action = sub_action; } /* * If rule_action has a RETURNING clause, then either throw it away if the * triggering query has no RETURNING clause, or rewrite it to emit what * the triggering query's RETURNING clause asks for. Throw an error if * more than one rule has a RETURNING clause. */ if (!parsetree->returningList) rule_action->returningList = NIL; else if (rule_action->returningList) { if (*returning_flag) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot have RETURNING lists in multiple rules"))); *returning_flag = true; rule_action->returningList = (List*)ResolveNew((Node*)parsetree->returningList, linitial_int(parsetree->resultRelations), 0, rt_fetch(linitial_int(parsetree->resultRelations), parsetree->rtable), rule_action->returningList, CMD_SELECT, 0, &rule_action->hasSubLinks); /* * There could have been some SubLinks in parsetree's returningList, * in which case we'd better mark the rule_action correctly. */ if (parsetree->hasSubLinks && !rule_action->hasSubLinks) rule_action->hasSubLinks = checkExprHasSubLink((Node*)rule_action->returningList); } return rule_action; } /* * Copy the query's jointree list, and optionally attempt to remove any * occurrence of the given rt_index as a top-level join item (we do not look * for it within join items; this is OK because we are only expecting to find * it as an UPDATE or DELETE target relation, which will be at the top level * of the join). Returns modified jointree list --- this is a separate copy * sharing no nodes with the original. */ static List* adjustJoinTreeList(Query* parsetree, bool removert, int rt_index) { List* newjointree = (List*)copyObject(parsetree->jointree->fromlist); ListCell* l = NULL; if (removert) { foreach (l, newjointree) { RangeTblRef* rtr = (RangeTblRef*)lfirst(l); if (IsA(rtr, RangeTblRef) && rtr->rtindex == rt_index) { newjointree = list_delete_ptr(newjointree, rtr); /* * foreach is safe because we exit loop after list_delete... */ break; } } } return newjointree; } /* * rewriteTargetListIU - rewrite INSERT/UPDATE targetlist into standard form * * This has the following responsibilities: * * 1. For an INSERT, add tlist entries to compute default values for any * attributes that have defaults and are not assigned to in the given tlist. * (We do not insert anything for default-less attributes, however. The * planner will later insert NULLs for them, but there's no reason to slow * down rewriter processing with extra tlist nodes.) Also, for both INSERT * and UPDATE, replace explicit DEFAULT specifications with column default * expressions. * * 2. For an UPDATE on a view, add tlist entries for any unassigned-to * attributes, assigning them their old values. These will later get * expanded to the output values of the view. (This is equivalent to what * the planner's expand_targetlist() will do for UPDATE on a regular table, * but it's more convenient to do it here while we still have easy access * to the view's original RT index.) * * 3. Merge multiple entries for the same target attribute, or declare error * if we can't. Multiple entries are only allowed for INSERT/UPDATE of * portions of an array or record field, for example * UPDATE table SET foo[2] = 42, foo[4] = 43; * We can merge such operations into a single assignment op. Essentially, * the expression we want to produce in this case is like * foo = array_set(array_set(foo, 2, 42), 4, 43) * * 4. Sort the tlist into standard order: non-junk fields in order by resno, * then junk fields (these in no particular order). * * We must do items 1,2,3 before firing rewrite rules, else rewritten * references to NEW.foo will produce wrong or incomplete results. Item 4 * is not needed for rewriting, but will be needed by the planner, and we * can do it essentially for free while handling the other items. * * If attrno_list isn't NULL, we return an additional output besides the * rewritten targetlist: an integer list of the assigned-to attnums, in * order of the original tlist's non-junk entries. This is needed for * processing VALUES RTEs. */ static List* rewriteTargetListIU(List* targetList, CmdType commandType, Relation target_relation, int result_rtindex, List** attrno_list, bool* hasGenCol) { TargetEntry** new_tles; List* new_tlist = NIL; List* junk_tlist = NIL; Form_pg_attribute att_tup; int attrno, next_junk_attrno, numattrs; ListCell* temp = NULL; if (attrno_list != NULL) /* initialize optional result list */ *attrno_list = NIL; /* * We process the normal (non-junk) attributes by scanning the input tlist * once and transferring TLEs into an array, then scanning the array to * build an output tlist. This avoids O(N^2) behavior for large numbers * of attributes. * * Junk attributes are tossed into a separate list during the same tlist * scan, then appended to the reconstructed tlist. */ numattrs = RelationGetNumberOfAttributes(target_relation); new_tles = (TargetEntry**)palloc0(numattrs * sizeof(TargetEntry*)); next_junk_attrno = numattrs + 1; foreach (temp, targetList) { TargetEntry* old_tle = (TargetEntry*)lfirst(temp); if (!old_tle->resjunk) { /* Normal attr: stash it into new_tles[] */ attrno = old_tle->resno; if (attrno < 1 || attrno > numattrs) { ereport(ERROR, (errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("bogus resno %d in targetlist", attrno))); } att_tup = target_relation->rd_att->attrs[attrno - 1]; /* put attrno into attrno_list even if it's dropped */ if (attrno_list != NULL) *attrno_list = lappend_int(*attrno_list, attrno); /* We can (and must) ignore deleted attributes */ if (att_tup->attisdropped) continue; /* Merge with any prior assignment to same attribute */ new_tles[attrno - 1] = process_matched_tle(old_tle, new_tles[attrno - 1], NameStr(att_tup->attname)); } else { /* * Copy all resjunk tlist entries to junk_tlist, and assign them * resnos above the last real resno. * * Typical junk entries include ORDER BY or GROUP BY expressions * (are these actually possible in an INSERT or UPDATE?), system * attribute references, etc. * * Get the resno right, but don't copy unnecessarily */ if (old_tle->resno != next_junk_attrno) { old_tle = flatCopyTargetEntry(old_tle); old_tle->resno = next_junk_attrno; } junk_tlist = lappend(junk_tlist, old_tle); next_junk_attrno++; } } for (attrno = 1; attrno <= numattrs; attrno++) { TargetEntry* new_tle = new_tles[attrno - 1]; bool applyDefault = false; bool generateCol = ISGENERATEDCOL(target_relation->rd_att, attrno - 1); att_tup = target_relation->rd_att->attrs[attrno - 1]; /* We can (and must) ignore deleted attributes */ if (att_tup->attisdropped) continue; /* * Handle the two cases where we need to insert a default expression: * it's an INSERT and there's no tlist entry for the column, or the * tlist entry is a DEFAULT placeholder node. */ applyDefault = ((new_tle == NULL && commandType == CMD_INSERT) || (new_tle != NULL && new_tle->expr != NULL && IsA(new_tle->expr, SetToDefault))); if (generateCol && !applyDefault) { if (commandType == CMD_INSERT && attrno_list == NULL) { ereport(ERROR, (errmodule(MOD_GEN_COL), errcode(ERRCODE_SYNTAX_ERROR), errmsg("cannot insert into column \"%s\"", NameStr(att_tup->attname)), errdetail("Column \"%s\" is a generated column.", NameStr(att_tup->attname)))); } if (commandType == CMD_UPDATE && new_tle) { ereport(ERROR, (errmodule(MOD_GEN_COL), errcode(ERRCODE_SYNTAX_ERROR), errmsg("column \"%s\" can only be updated to DEFAULT", NameStr(att_tup->attname)), errdetail("Column \"%s\" is a generated column.", NameStr(att_tup->attname)))); } } if (generateCol) { /* * stored generated column will be fixed in executor */ new_tle = NULL; *hasGenCol = true; } else if (applyDefault) { Node* new_expr = NULL; new_expr = build_column_default(target_relation, attrno, true); /* * If there is no default (ie, default is effectively NULL), we * can omit the tlist entry in the INSERT case, since the planner * can insert a NULL for itself, and there's no point in spending * any more rewriter cycles on the entry. But in the UPDATE case * we've got to explicitly set the column to NULL. */ if (new_expr == NULL) { if (commandType == CMD_INSERT) { new_tle = NULL; ereport(DEBUG2, (errmodule(MOD_PARSER), errcode(ERRCODE_LOG), errmsg("default column \"%s\" is effectively NULL, and hence omitted.", NameStr(att_tup->attname)))); } else { new_expr = (Node*)makeConst(att_tup->atttypid, -1, att_tup->attcollation, att_tup->attlen, (Datum)0, true, /* isnull */ att_tup->attbyval); /* this is to catch a NOT NULL domain constraint */ new_expr = coerce_to_domain( new_expr, InvalidOid, -1, att_tup->atttypid, COERCE_IMPLICIT_CAST, -1, false, false); } } if (new_expr != NULL) new_tle = makeTargetEntry((Expr*)new_expr, attrno, pstrdup(NameStr(att_tup->attname)), false); } /* * For an UPDATE on a view, provide a dummy entry whenever there is no * explicit assignment. */ if (new_tle == NULL && commandType == CMD_UPDATE && (target_relation->rd_rel->relkind == RELKIND_VIEW || target_relation->rd_rel->relkind == RELKIND_CONTQUERY)) { Node* new_expr = NULL; new_expr = (Node*)makeVar( result_rtindex, attrno, att_tup->atttypid, att_tup->atttypmod, att_tup->attcollation, 0); new_tle = makeTargetEntry((Expr*)new_expr, attrno, pstrdup(NameStr(att_tup->attname)), false); } if (new_tle != NULL) new_tlist = lappend(new_tlist, new_tle); } pfree_ext(new_tles); targetList = list_concat(new_tlist, junk_tlist); return targetList; } static void rewriteTargetListMutilUpdate(Query* parsetree, List* rtable, List* resultRelations) { TargetEntry** new_tles; List* new_tlist = NIL; List* junk_tlist = NIL; Form_pg_attribute att_tup; int attrno, numattrs; ListCell* l = NULL; int result_relation; /* * We process the normal (non-junk) attributes by scanning the input tlist * once and transferring TLEs into an array, then scanning the array to * build an output tlist. This avoids O(N^2) behavior for large numbers * of attributes. * * Junk attributes are tossed into a separate list during the same tlist * scan, then appended to the reconstructed tlist. */ ListCell* temp = list_head(parsetree->targetList); TargetEntry* old_tle = (TargetEntry*)lfirst(temp); foreach (l, resultRelations) { result_relation = lfirst_int(l); Assert(((TargetEntry*)lfirst(temp))->rtindex == (Index)result_relation); RangeTblEntry* rt_entry = rt_fetch(result_relation, rtable); Relation target_relation = heap_open(rt_entry->relid, NoLock); numattrs = RelationGetNumberOfAttributes(target_relation); new_tles = (TargetEntry**)palloc0(numattrs * sizeof(TargetEntry*)); while (temp != NULL) { old_tle = (TargetEntry*)lfirst(temp); /* * For multi-relations update, old_tle has been sorted according to the order of each result relation. * So when old_tle->rtindex != (Index)result_relation, break and process the next step. */ if (old_tle->rtindex != (Index)result_relation) break; if (!old_tle->resjunk) { /* Normal attr: stash it into new_tles[] */ attrno = old_tle->resno; if (attrno < 1 || attrno > numattrs) { ereport(ERROR, (errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("bogus resno %d in targetlist", attrno))); } att_tup = target_relation->rd_att->attrs[attrno - 1]; /* We can (and must) ignore deleted attributes */ if (att_tup->attisdropped) { temp = lnext(temp); continue; } /* Merge with any prior assignment to same attribute */ new_tles[attrno - 1] = process_matched_tle(old_tle, new_tles[attrno - 1], NameStr(att_tup->attname)); } else { /* * Copy all resjunk tlist entries to junk_tlist, and assign them * resnos above the last real resno. * * Typical junk entries include ORDER BY or GROUP BY expressions * (are these actually possible in an INSERT or UPDATE?), system * attribute references, etc. * * Get the resno right, but don't copy unnecessarily */ old_tle = flatCopyTargetEntry(old_tle); junk_tlist = lappend(junk_tlist, old_tle); } temp = lnext(temp); } for (attrno = 1; attrno <= numattrs; attrno++) { TargetEntry* new_tle = new_tles[attrno - 1]; /* * We need to insert a default expression when the * tlist entry is a DEFAULT placeholder node. */ bool applyDefault = new_tle != NULL && new_tle->expr != NULL && IsA(new_tle->expr, SetToDefault); bool generateCol = ISGENERATEDCOL(target_relation->rd_att, attrno - 1); att_tup = target_relation->rd_att->attrs[attrno - 1]; /* We can (and must) ignore deleted attributes */ if (att_tup->attisdropped) continue; if (generateCol && !applyDefault && new_tle) { ereport(ERROR, (errmodule(MOD_GEN_COL), errcode(ERRCODE_SYNTAX_ERROR), errmsg("column \"%s\" can only be updated to DEFAULT", NameStr(att_tup->attname)), errdetail("Column \"%s\" is a generated column.", NameStr(att_tup->attname)))); } if (generateCol) { /* * stored generated column will be fixed in executor */ new_tle = NULL; } else if (applyDefault) { Node* new_expr = build_column_default(target_relation, attrno, true); if (new_expr == NULL) { new_expr = (Node*)makeConst(att_tup->atttypid, -1, att_tup->attcollation, att_tup->attlen, (Datum)0, true, /* isnull */ att_tup->attbyval); /* this is to catch a NOT NULL domain constraint */ new_expr = coerce_to_domain( new_expr, InvalidOid, -1, att_tup->atttypid, COERCE_IMPLICIT_CAST, -1, false, false); } new_tle = makeTargetEntry((Expr*)new_expr, attrno, pstrdup(NameStr(att_tup->attname)), false); new_tle->rtindex = result_relation; } /* * For an UPDATE on a view, provide a dummy entry whenever there is no * explicit assignment. */ if (new_tle == NULL && (target_relation->rd_rel->relkind == RELKIND_VIEW || target_relation->rd_rel->relkind == RELKIND_CONTQUERY)) { Node* new_expr = NULL; new_expr = (Node*)makeVar( result_relation, attrno, att_tup->atttypid, att_tup->atttypmod, att_tup->attcollation, 0); new_tle = makeTargetEntry((Expr*)new_expr, attrno, pstrdup(NameStr(att_tup->attname)), false); new_tle->rtindex = result_relation; } if (new_tle != NULL) new_tlist = lappend(new_tlist, new_tle); } heap_close(target_relation, NoLock); pfree_ext(new_tles); } int next_junk_attrno = list_length(new_tlist) + 1; foreach (l, junk_tlist) { old_tle = (TargetEntry*)lfirst(l); if (old_tle->resno != next_junk_attrno) { old_tle = flatCopyTargetEntry(old_tle); old_tle->resno = next_junk_attrno; } new_tlist = lappend(new_tlist, old_tle); next_junk_attrno++; } parsetree->targetList = new_tlist; rewriteTargetListMutilUD(parsetree, rtable, resultRelations); } /* * Convert a matched TLE from the original tlist into a correct new TLE. * * This routine detects and handles multiple assignments to the same target * attribute. (The attribute name is needed only for error messages.) */ static TargetEntry* process_matched_tle(TargetEntry* src_tle, TargetEntry* prior_tle, const char* attrName) { TargetEntry* result = NULL; Node* src_expr = NULL; Node* prior_expr = NULL; Node* src_input = NULL; Node* prior_input = NULL; Node* priorbottom = NULL; Node* newexpr = NULL; errno_t errorno = EOK; if (prior_tle == NULL) { /* * Normal case where this is the first assignment to the attribute. */ return src_tle; } /* ---------- * Multiple assignments to same attribute. Allow only if all are * FieldStore or ArrayRef assignment operations. This is a bit * tricky because what we may actually be looking at is a nest of * such nodes; consider * UPDATE tab SET col.fld1.subfld1 = x, col.fld2.subfld2 = y * The two expressions produced by the parser will look like * FieldStore(col, fld1, FieldStore(placeholder, subfld1, x)) * FieldStore(col, fld2, FieldStore(placeholder, subfld2, x)) * However, we can ignore the substructure and just consider the top * FieldStore or ArrayRef from each assignment, because it works to * combine these as * FieldStore(FieldStore(col, fld1, * FieldStore(placeholder, subfld1, x)), * fld2, FieldStore(placeholder, subfld2, x)) * Note the leftmost expression goes on the inside so that the * assignments appear to occur left-to-right. * * For FieldStore, instead of nesting we can generate a single * FieldStore with multiple target fields. We must nest when * ArrayRefs are involved though. * ---------- */ src_expr = (Node*)src_tle->expr; prior_expr = (Node*)prior_tle->expr; src_input = get_assignment_input(src_expr); prior_input = get_assignment_input(prior_expr); if (src_input == NULL || prior_input == NULL || exprType(src_expr) != exprType(prior_expr)) { ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("multiple assignments to same column \"%s\"", attrName))); } /* * Prior TLE could be a nest of assignments if we do this more than once. */ priorbottom = prior_input; for (;;) { Node* newbottom = get_assignment_input(priorbottom); if (newbottom == NULL) { break; /* found the original Var reference */ } priorbottom = newbottom; } if (!equal(priorbottom, src_input)) { ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("multiple assignments to same column \"%s\"", attrName))); } /* * Looks OK to nest 'em. */ size_t fstore_len = sizeof(FieldStore); if (IsA(src_expr, FieldStore)) { FieldStore* fstore = makeNode(FieldStore); if (IsA(prior_expr, FieldStore)) { /* combine the two */ errorno = memcpy_s(fstore, fstore_len, prior_expr, fstore_len); securec_check(errorno, "\0", "\0"); fstore->newvals = list_concat(list_copy(((FieldStore*)prior_expr)->newvals), list_copy(((FieldStore*)src_expr)->newvals)); fstore->fieldnums = list_concat( list_copy(((FieldStore*)prior_expr)->fieldnums), list_copy(((FieldStore*)src_expr)->fieldnums)); } else { /* general case, just nest 'em */ errorno = memcpy_s(fstore, fstore_len, src_expr, fstore_len); securec_check(errorno, "\0", "\0"); fstore->arg = (Expr*)prior_expr; } newexpr = (Node*)fstore; } else if (IsA(src_expr, ArrayRef)) { ArrayRef* aref = makeNode(ArrayRef); errorno = memcpy_s(aref, sizeof(ArrayRef), src_expr, sizeof(ArrayRef)); securec_check(errorno, "\0", "\0"); aref->refexpr = (Expr*)prior_expr; newexpr = (Node*)aref; } else { ereport(ERROR, (errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("cannot happen"))); newexpr = NULL; } result = flatCopyTargetEntry(src_tle); result->expr = (Expr*)newexpr; return result; } /* * If node is an assignment node, return its input; else return NULL */ static Node* get_assignment_input(Node* node) { if (node == NULL) return NULL; if (IsA(node, FieldStore)) { FieldStore* fstore = (FieldStore*)node; return (Node*)fstore->arg; } else if (IsA(node, ArrayRef)) { ArrayRef* aref = (ArrayRef*)node; if (aref->refassgnexpr == NULL) return NULL; return (Node*)aref->refexpr; } return NULL; } static bool check_sequence_return_numeric_walker(Node *node, int *ret) { /* Traverse through the expression tree and check requence related function return type */ if (node == NULL) { *ret = NDE_UNKNOWN; return false; } if (IsA(node, Query)) { return (Node *)query_tree_walker((Query *)node, (bool (*)())check_sequence_return_numeric_walker, (void *)ret, 0); } if (IsA(node, FuncExpr)) { FuncExpr *func = (FuncExpr *)node; if (func->funcid == NEXTVALFUNCOID || func->funcid == CURRVALFUNCOID || func->funcid == LASTVALFUNCOID) { if (func->funcresulttype == NUMERICOID) { *ret = NDE_NUMERIC; return true; } else { *ret = NDE_BIGINT; return true; } } } return expression_tree_walker(node, (bool (*)())check_sequence_return_numeric_walker, (void *)ret); } /* * Make an expression tree for the default value for a column. * * If there is no default, return a NULL instead. * Add one input arg isInsertCmd to show if current statement is insert. * If auto truncation function enabled and it is insert statement then * we use this arg to determin if default should be casted explict. */ Node* build_column_default(Relation rel, int attrno, bool isInsertCmd, bool needOnUpdate) { TupleDesc rd_att = rel->rd_att; Form_pg_attribute att_tup = rd_att->attrs[attrno - 1]; Oid atttype = att_tup->atttypid; int32 atttypmod = att_tup->atttypmod; Node* expr = NULL; Oid exprtype; /* * Scan to see if relation has a default for this column. */ if (rd_att->constr && rd_att->constr->num_defval > 0) { AttrDefault* defval = rd_att->constr->defval; int ndef = rd_att->constr->num_defval; while (--ndef >= 0) { if (attrno == defval[ndef].adnum) { /* * Found it, convert string representation to node tree. * * isInsertCmd is false, has_on_update is true and adbin_on_update is not null character string, * then doing convert adbin_on_update to expression. * if adbin is not null character string, then doing convert adbin to expression. */ if (needOnUpdate && (!isInsertCmd) && defval[ndef].has_on_update && pg_strcasecmp(defval[ndef].adbin_on_update, "") != 0) { expr = (Node*)stringToNode_skip_extern_fields(defval[ndef].adbin_on_update); } else { if (pg_strcasecmp(defval[ndef].adbin, "") != 0) { expr = (Node*)stringToNode_skip_extern_fields(defval[ndef].adbin); } } if (t_thrd.proc->workingVersionNum < LARGE_SEQUENCE_VERSION_NUM) { (void)check_sequence_return_numeric_walker(expr, &(u_sess->opt_cxt.nextval_default_expr_type)); } break; } } } if (expr == NULL && !ISGENERATEDCOL(rd_att, attrno - 1)) { /* * No per-column default, so look for a default for the type itself.But * not for generated columns. */ expr = get_typdefault(atttype); } if (expr == NULL) return NULL; /* No default anywhere */ if (IsA(expr, AutoIncrement)) { expr = (Node*)makeConst(INT4OID, -1, InvalidOid, sizeof(int32), Int32GetDatum(0), !att_tup->attnotnull, true); } /* * Make sure the value is coerced to the target column type; this will * generally be true already, but there seem to be some corner cases * involving domain defaults where it might not be true. This should match * the parser's processing of non-defaulted expressions --- see * transformAssignedExpr(). */ exprtype = exprType(expr); expr = coerce_to_target_type(NULL, /* no UNKNOWN params here */ expr, exprtype, atttype, atttypmod, COERCION_ASSIGNMENT, COERCE_IMPLICIT_CAST, -1); /* * When td_compatible_truncation is set to on, this part of code will set column default * value to isExplicte args to true, to let bpchar know one explict cast has been added to * this default value already. */ if (u_sess->attr.attr_sql.td_compatible_truncation && u_sess->attr.attr_sql.sql_compatibility == C_FORMAT && isInsertCmd && (atttype == BPCHAROID || atttype == VARCHAROID) && expr != NULL) { AssertEreport(IsA(expr, FuncExpr), MOD_OPT, ""); FuncExpr* fe = (FuncExpr*)expr; Const* const_arg = (Const*)llast(fe->args); if (IsA(const_arg, Const) && const_arg->consttype == BOOLOID) const_arg->constvalue = (Datum) true; } if (expr == NULL) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("column \"%s\" is of type %s but %s expression is of type %s", NameStr(att_tup->attname), format_type_be(atttype), ISGENERATEDCOL(rd_att, attrno - 1) ? "generated column" : "deault", format_type_be(exprtype)), errhint("You will need to rewrite or cast the expression."))); /* * If there is nextval FuncExpr, we should lock the quoted sequence to avoid deadlock, * this has beed done in transformFuncExpr. See lockNextvalOnCn for more details. */ (void)lockNextvalWalker(expr, NULL); return expr; } /* Does VALUES RTE contain any SetToDefault items? */ static bool searchForDefault(RangeTblEntry* rte) { ListCell* lc = NULL; foreach (lc, rte->values_lists) { List* sublist = (List*)lfirst(lc); ListCell* lc2 = NULL; foreach (lc2, sublist) { Node* col = (Node*)lfirst(lc2); if (IsA(col, SetToDefault)) return true; } } return false; } static void checkGenDefault(RangeTblEntry* rte, Relation target_relation, List* attrnos, bool hasGenCol) { ListCell* lc = NULL; if (!hasGenCol) { return ; } foreach (lc, rte->values_lists) { List* sublist = (List*)lfirst(lc); ListCell* lc2 = NULL; ListCell* lc3 = NULL; forboth (lc2, sublist, lc3, attrnos) { Node* col = (Node*)lfirst(lc2); int attrno = lfirst_int(lc3); Form_pg_attribute att_tup = target_relation->rd_att->attrs[attrno - 1]; bool generatedCol = ISGENERATEDCOL(target_relation->rd_att, attrno - 1); bool applyDefault = IsA(col, SetToDefault); if (!applyDefault && generatedCol) ereport(ERROR, (errmodule(MOD_GEN_COL), errcode(ERRCODE_SYNTAX_ERROR), errmsg("cannot insert into column \"%s\"", NameStr(att_tup->attname)), errdetail("Column \"%s\" is a generated column.", NameStr(att_tup->attname)))); } } } /* * When processing INSERT ... VALUES with a VALUES RTE (ie, multiple VALUES * lists), we have to replace any DEFAULT items in the VALUES lists with * the appropriate default expressions. The other aspects of targetlist * rewriting need be applied only to the query's targetlist proper. * * Note that we currently can't support subscripted or field assignment * in the multi-VALUES case. The targetlist will contain simple Vars * referencing the VALUES RTE, and therefore process_matched_tle() will * reject any such attempt with "multiple assignments to same column". */ static void rewriteValuesRTE(RangeTblEntry* rte, Relation target_relation, List* attrnos) { List* newValues = NIL; ListCell* lc = NULL; /* * Rebuilding all the lists is a pretty expensive proposition in a big * VALUES list, and it's a waste of time if there aren't any DEFAULT * placeholders. So first scan to see if there are any. */ if (!searchForDefault(rte)) return; /* nothing to do */ /* Check list lengths (we can assume all the VALUES sublists are alike) */ AssertEreport(list_length(attrnos) == list_length((const List*)linitial(rte->values_lists)), MOD_OPT, ""); newValues = NIL; foreach (lc, rte->values_lists) { List* sublist = (List*)lfirst(lc); List* newList = NIL; ListCell* lc2 = NULL; ListCell* lc3 = NULL; forboth(lc2, sublist, lc3, attrnos) { Node *col = (Node *)lfirst(lc2); int attrno = lfirst_int(lc3); Form_pg_attribute att_tup = target_relation->rd_att->attrs[attrno - 1]; bool generatedCol = ISGENERATEDCOL(target_relation->rd_att, attrno - 1); bool applyDefault = IsA(col, SetToDefault); if (applyDefault) { Node *new_expr = NULL; /* stored generated column will be computed in executor */ if (att_tup->attisdropped || generatedCol) new_expr = NULL; else new_expr = build_column_default(target_relation, attrno, true); /* * If there is no default (ie, default is effectively NULL), * we've got to explicitly set the column to NULL. */ if (new_expr == NULL) { new_expr = (Node*)makeConst(att_tup->atttypid, -1, att_tup->attcollation, att_tup->attlen, (Datum)0, true, /* isnull */ att_tup->attbyval); /* this is to catch a NOT NULL domain constraint */ new_expr = coerce_to_domain( new_expr, InvalidOid, -1, att_tup->atttypid, COERCE_IMPLICIT_CAST, -1, false, false); } newList = lappend(newList, new_expr); } else { newList = lappend(newList, col); } } newValues = lappend(newValues, newList); } rte->values_lists = newValues; } #ifdef PGXC /* * pull_qual_vars(Node *node, int varno) * Extract vars from quals belonging to resultRelation. This function is mainly * taken from pull_qual_vars_clause(), but since the later does not peek into * subquery, we need to write this walker. * * @param (in) varno: * the varno of result relation * pull_qual_vars will returen all vars in current level if do NOT set 'varno' param * * @return: * (1) vars from quals belonging to resultRelation * (2) all vars from quals if 'varno' is not set */ List* pull_qual_vars(Node* node, int varno, int flags, bool nonRepeat) { pull_qual_vars_context context; context.varlist = NIL; context.sublevels_up = 0; context.resultRelation = varno; context.noRepeat = nonRepeat; (void)query_or_expression_tree_walker(node, (bool (*)())pull_qual_vars_walker, (void*)&context, flags); return context.varlist; } static bool pull_qual_vars_walker(Node* node, pull_qual_vars_context* context) { if (node == NULL) return false; if (IsA(node, Var)) { Var* var = (Var*)node; /* * Add only if this var belongs to the resultRelation and refers to the table * from the same query. * BUT==> if context->resultRelation is not set, * all var(s) refers to the table from the same query will be included */ if ((context->resultRelation == 0 || var->varno == (Index)context->resultRelation) && var->varlevelsup == (Index)context->sublevels_up) { if (context->noRepeat && list_member(context->varlist, var)) return false; Var* newvar = (Var*)copyObject(var); newvar->varlevelsup = 0; context->varlist = lappend(context->varlist, newvar); } return false; } if (IsA(node, Query)) { /* Recurse into RTE subquery or not-yet-planned sublink subquery */ bool result = false; context->sublevels_up++; result = query_tree_walker((Query*)node, (bool (*)())pull_qual_vars_walker, (void*)context, 0); context->sublevels_up--; return result; } return expression_tree_walker(node, (bool (*)())pull_qual_vars_walker, (void*)context); } #endif /* PGXC */ /* * rewriteTargetListUD - rewrite UPDATE/DELETE targetlist as needed * * This function adds a "junk" TLE that is needed to allow the executor to * find the original row for the update or delete. When the target relation * is a regular table, the junk TLE emits the ctid attribute of the original * row. When the target relation is a view, there is no ctid, so we instead * emit a whole-row Var that will contain the "old" values of the view row. * If it's a foreign table, we let the FDW decide what to add. * * For UPDATE queries, this is applied after rewriteTargetListIU. The * ordering isn't actually critical at the moment. */ static void rewriteTargetListUD(Query* parsetree, RangeTblEntry* target_rte, Relation target_relation, int rtindex) { Var* var = NULL; const char* attrname = NULL; TargetEntry* tle = NULL; #ifdef PGXC List* var_list = NIL; ListCell* elt = NULL; /* * In openGauss, we need to evaluate quals of the parse tree and determine * if they are Coordinator quals. If they are, their attribute need to be * added to target list for evaluation. In case some are found, add them as * junks in the target list. The junk status will be used by remote UPDATE * planning to associate correct element to a clause. * For DELETE, having such columns in target list helps to evaluate Quals * correctly on Coordinator. * This list could be reduced to keep only in target list the * vars using Coordinator Quals. */ if (IS_PGXC_COORDINATOR && parsetree->jointree) var_list = pull_qual_vars((Node*)parsetree->jointree, rtindex); foreach (elt, var_list) { Form_pg_attribute att_tup; int numattrs = RelationGetNumberOfAttributes(target_relation); var = (Var*)lfirst(elt); /* Bypass in case of extra target items like ctid */ if (var->varattno < 1 || var->varattno > numattrs) { if (var->varattno < 1) { RangeTblEntry* rte = rt_fetch(var->varno, parsetree->rtable); if (LOCATOR_TYPE_REPLICATED == GetLocatorType(rte->relid)) { t_thrd.postmaster_cxt.forceNoSeparate = true; } parsetree->equalVars = lappend(parsetree->equalVars, copyObject(var)); } continue; } att_tup = target_relation->rd_att->attrs[var->varattno - 1]; tle = makeTargetEntry( (Expr*)var, list_length(parsetree->targetList) + 1, pstrdup(NameStr(att_tup->attname)), true); tle->rtindex = rtindex; parsetree->targetList = lappend(parsetree->targetList, tle); } parsetree->equalVars = list_concat( parsetree->equalVars, pull_qual_vars((Node*)parsetree->targetList, rtindex, 0, true)); if (IS_PGXC_COORDINATOR && RelationGetLocInfo(target_relation) && IsRelationReplicated(RelationGetLocInfo(target_relation)) && RelationIsRelation(target_relation)) { int16* indexed_col = NULL; int index_col_count = 0; int counter = 0; index_col_count = pgxc_find_primarykey(target_relation->rd_id, &indexed_col); AssertEreport(index_col_count >= 0, MOD_OPT, ""); for (counter = 0; counter < index_col_count; counter++) { AttrNumber att_no = indexed_col[counter]; HeapTuple heaptuple = NULL; Form_pg_attribute att_tup = NULL; Node* new_expr = NULL; TargetEntry* new_tle = NULL; if (att_no > 0) { att_tup = target_relation->rd_att->attrs[att_no - 1]; } else { heaptuple = SearchSysCache2(ATTNUM, ObjectIdGetDatum(RelationGetRelid(target_relation)), Int16GetDatum(att_no)); if (!HeapTupleIsValid(heaptuple)) ereport(ERROR, (errcode(ERRCODE_CACHE_LOOKUP_FAILED), errmsg("cache lookup failed for attribute %d of relation %u", att_no, RelationGetRelid(target_relation)))); att_tup = (Form_pg_attribute)GETSTRUCT(heaptuple); } new_expr = (Node*)makeVar( rtindex, att_no, att_tup->atttypid, att_tup->atttypmod, att_tup->attcollation, 0); new_tle = makeTargetEntry((Expr*)new_expr, list_length(parsetree->targetList) + 1, "xc_primary_key", true); new_tle->rtindex = rtindex; parsetree->targetList = lappend(parsetree->targetList, new_tle); if (att_no <= 0) { ReleaseSysCache(heaptuple); } } } #endif if (target_relation->rd_rel->relkind == RELKIND_RELATION || target_relation->rd_rel->relkind == RELKIND_MATVIEW) { /* * Emit CTID so that executor can find the row to update or delete. */ var = makeVar(rtindex, SelfItemPointerAttributeNumber, TIDOID, -1, InvalidOid, 0); attrname = "ctid"; } else if (target_relation->rd_rel->relkind == RELKIND_FOREIGN_TABLE || target_relation->rd_rel->relkind == RELKIND_STREAM) { /* * Let the foreign table's FDW add whatever junk TLEs it wants. */ FdwRoutine* fdwroutine = NULL; fdwroutine = GetFdwRoutineForRelation(target_relation, false); if (fdwroutine->AddForeignUpdateTargets != NULL) fdwroutine->AddForeignUpdateTargets(parsetree, target_rte, target_relation); return; } else { /* * Emit whole-row Var so that executor will have the "old" view row to * pass to the INSTEAD OF trigger. */ var = makeWholeRowVar(target_rte, rtindex, 0, false); if (var == NULL) { ereport(ERROR,(errcode(ERRCODE_UNDEFINED_FILE), errmsg("Fail to get the previous view row."))); return; } attrname = "wholerow"; } tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup(attrname), true); tle->rtindex = rtindex; parsetree->targetList = lappend(parsetree->targetList, tle); /* if a partitioned table , need get tableOid column */ if (target_relation->rd_rel->relkind == RELKIND_RELATION && (RELATION_IS_PARTITIONED(target_relation) || RelationIsCUFormat(target_relation))) { var = makeVar(rtindex, TableOidAttributeNumber, OIDOID, -1, InvalidOid, 0); attrname = "tableoid"; tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup(attrname), true); tle->rtindex = rtindex; parsetree->targetList = lappend(parsetree->targetList, tle); } if (target_relation->rd_rel->relkind == RELKIND_RELATION && RELATION_HAS_BUCKET(target_relation)) { var = makeVar(rtindex, BucketIdAttributeNumber, INT2OID, -1, InvalidBktId, 0); attrname = "tablebucketid"; tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup(attrname), true); tle->rtindex = rtindex; parsetree->targetList = lappend(parsetree->targetList, tle); } #ifdef PGXC /* Add further attributes required for Coordinator */ if (IS_PGXC_COORDINATOR && RelationGetLocInfo(target_relation) != NULL && target_relation->rd_rel->relkind == RELKIND_RELATION) { /* * If relation is non-replicated, we need also to identify the Datanode * from where tuple is fetched. */ if (!IsRelationReplicated(RelationGetLocInfo(target_relation))) { var = makeVar(rtindex, XC_NodeIdAttributeNumber, INT4OID, -1, InvalidOid, 0); tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup("xc_node_id"), true); tle->rtindex = rtindex; parsetree->targetList = lappend(parsetree->targetList, tle); } /* For non-shippable triggers, we need OLD row. */ if (pgxc_trig_oldrow_reqd(target_relation, parsetree->commandType)) { var = makeWholeRowVar(target_rte, rtindex, 0, false); tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup("wholerow"), true); tle->rtindex = rtindex; parsetree->targetList = lappend(parsetree->targetList, tle); } } #endif } static void rewriteTargetListMutilUD(Query* parsetree, List* rtable, List* resultRelations) { ListCell* lc; int result_relation; RangeTblEntry* rt_entry = NULL; Relation rt_entry_relation; foreach (lc, resultRelations) { result_relation = lfirst_int(lc); rt_entry = rt_fetch(result_relation, rtable); AssertEreport(rt_entry->rtekind == RTE_RELATION, MOD_OPT, ""); rt_entry_relation = heap_open(rt_entry->relid, NoLock); rewriteTargetListUD(parsetree, rt_entry, rt_entry_relation, result_relation); heap_close(rt_entry_relation, NoLock); } } void rewriteTargetListMerge(Query* parsetree, Index result_relation, List* range_table) { Var* var = NULL; const char* attrname = NULL; TargetEntry* tle = NULL; Relation rel; /* * The rewriter should have already ensured that the TLEs are in correct * order; but we have to insert TLEs for any missing attributes. * * Scan the tuple description in the relation's relcache entry to make * sure we have all the user attributes in the right order. We assume * that the rewriter already acquired at least AccessShareLock on the * relation, so we need no lock here. */ rel = heap_open(getrelid(result_relation, range_table), NoLock); Assert(rel->rd_rel->relkind == RELKIND_RELATION); parsetree->targetList = expandTargetTL(parsetree->targetList, parsetree); /* * Emit CTID so that executor can find the row to update or delete. */ var = makeVar(parsetree->mergeTarget_relation, SelfItemPointerAttributeNumber, TIDOID, -1, InvalidOid, 0); attrname = "ctid"; tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup(attrname), true); parsetree->targetList = lappend(parsetree->targetList, tle); /* We need add xc_node_id for MPP cluster mode, but only ctid for single datanode */ if (IS_PGXC_COORDINATOR) { /* * Emit xc_node_id so that executor can find the row to update or delete. */ var = makeVar(parsetree->mergeTarget_relation, XC_NodeIdAttributeNumber, INT4OID, -1, InvalidOid, 0); attrname = "xc_node_id"; tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup(attrname), true); parsetree->targetList = lappend(parsetree->targetList, tle); } /* * If we are dealing with partitioned table, then emit TABLEOID so that * executor can find the partition the row belongs to. */ if (RELATION_IS_PARTITIONED(rel) || RelationIsCUFormat(rel)) { var = makeVar(parsetree->mergeTarget_relation, TableOidAttributeNumber, OIDOID, -1, InvalidOid, 0); attrname = "tableoid"; tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup(attrname), true); parsetree->targetList = lappend(parsetree->targetList, tle); } if (RELATION_HAS_BUCKET(rel)) { var = makeVar(parsetree->mergeTarget_relation, BucketIdAttributeNumber, INT2OID, -1, InvalidBktId, 0); attrname = "tablebucketid"; tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup(attrname), true); parsetree->targetList = lappend(parsetree->targetList, tle); } heap_close(rel, NoLock); } /* * matchLocks - * match the list of locks and returns the matching rules */ static List* matchLocks(CmdType event, RuleLock* rulelocks, int varno, Query* parsetree) { List* matching_locks = NIL; int nlocks; int i; if (rulelocks == NULL) return NIL; if (parsetree->commandType != CMD_SELECT) { if (linitial2_int(parsetree->resultRelations) != varno) return NIL; } nlocks = rulelocks->numLocks; for (i = 0; i < nlocks; i++) { RewriteRule* oneLock = rulelocks->rules[i]; /* * Suppress ON INSERT/UPDATE/DELETE rules that are disabled or * configured to not fire during the current sessions replication * role. ON SELECT rules will always be applied in order to keep views * working even in LOCAL or REPLICA role. */ if (oneLock->event != CMD_SELECT) { if (u_sess->attr.attr_common.SessionReplicationRole == SESSION_REPLICATION_ROLE_REPLICA) { if (oneLock->enabled == RULE_FIRES_ON_ORIGIN || oneLock->enabled == RULE_DISABLED) continue; } else { /* ORIGIN or LOCAL ROLE */ if (oneLock->enabled == RULE_FIRES_ON_REPLICA || oneLock->enabled == RULE_DISABLED) continue; } } if (oneLock->event == event) { if (parsetree->commandType != CMD_SELECT || (oneLock->attrno == -1 ? rangeTableEntry_used((Node*)parsetree, varno, 0) : attribute_used((Node*)parsetree, varno, oneLock->attrno, 0))) matching_locks = lappend(matching_locks, oneLock); } } return matching_locks; } /* * ApplyRetrieveRule - expand an ON SELECT rule */ static Query* ApplyRetrieveRule(Query* parsetree, RewriteRule* rule, int rt_index, bool relation_level, Relation relation, List* activeRIRs, bool forUpdatePushedDown) { Query* rule_action = NULL; RangeTblEntry* rte = NULL; RangeTblEntry* subrte = NULL; RowMarkClause* rc = NULL; if (list_length(rule->actions) != 1) { ereport(ERROR, (errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("expected just one rule action"))); } if (rule->qual != NULL) { ereport( ERROR, (errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("cannot handle qualified ON SELECT rule"))); } if (!relation_level) { ereport(ERROR, (errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("cannot handle per-attribute ON SELECT rule"))); } if (rt_index == linitial2_int(parsetree->resultRelations)) { /* * We have a view as the result relation of the query, and it wasn't * rewritten by any rule. This case is supported if there is an * INSTEAD OF trigger that will trap attempts to insert/update/delete * view rows. The executor will check that; for the moment just plow * ahead. We have two cases: * * For INSERT, we needn't do anything. The unmodified RTE will serve * fine as the result relation. * * For UPDATE/DELETE, we need to expand the view so as to have source * data for the operation. But we also need an unmodified RTE to * serve as the target. So, copy the RTE and add the copy to the * rangetable. Note that the copy does not get added to the jointree. * Also note that there's a hack in fireRIRrules to avoid calling this * function again when it arrives at the copied RTE. */ if (parsetree->commandType == CMD_INSERT) return parsetree; else if (parsetree->commandType == CMD_UPDATE || parsetree->commandType == CMD_DELETE) { RangeTblEntry* newrte = NULL; rte = rt_fetch(rt_index, parsetree->rtable); newrte = (RangeTblEntry*)copyObject(rte); parsetree->rtable = (List*)lappend(parsetree->rtable, newrte); linitial_int(parsetree->resultRelations) = list_length(parsetree->rtable); parsetree->resultRelation = linitial_int(parsetree->resultRelations); /* * There's no need to do permissions checks twice, so wipe out the * permissions info for the original RTE (we prefer to keep the * bits set on the result RTE). */ rte->requiredPerms = 0; rte->checkAsUser = InvalidOid; rte->selectedCols = NULL; rte->insertedCols = NULL; rte->updatedCols = NULL; rte->extraUpdatedCols = NULL; /* * For the most part, Vars referencing the view should remain as * they are, meaning that they implicitly represent OLD values. * But in the RETURNING list if any, we want such Vars to * represent NEW values, so change them to reference the new RTE. * * Since ChangeVarNodes scribbles on the tree in-place, copy the * RETURNING list first for safety. */ parsetree->returningList = (List*)copyObject(parsetree->returningList); ChangeVarNodes((Node*)parsetree->returningList, rt_index, linitial2_int(parsetree->resultRelations), 0); /* Now, continue with expanding the original view RTE */ } else { ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("unrecognized commandType: %d", (int)parsetree->commandType))); } } /* * If FOR [KEY] UPDATE/SHARE of view, be sure we get right initial lock on the * relations it references. */ rc = get_parse_rowmark(parsetree, rt_index); forUpdatePushedDown = forUpdatePushedDown || (rc != NULL); /* * Make a modifiable copy of the view query, and acquire needed locks on * the relations it mentions. */ rule_action = (Query*)copyObject(linitial(rule->actions)); AcquireRewriteLocks(rule_action, forUpdatePushedDown); /* * If FOR [KEY] UPDATE/SHARE of view, mark all the contained tables as implicit * FOR [KEY] UPDATE/SHARE, the same as the parser would have done if the view's * subquery had been written out explicitly. * * Note: we don't consider forUpdatePushedDown here; such marks will be * made by recursing from the upper level in markQueryForLocking. */ if (rc != NULL) markQueryForLocking(rule_action, (Node*)rule_action->jointree, rc->strength, rc->waitPolicy, true, rc->waitSec); /* * Recursively expand any view references inside the view. * * Note: this must happen after markQueryForLocking. That way, any UPDATE * permission bits needed for sub-views are initially applied to their * RTE_RELATION RTEs by markQueryForLocking, and then transferred to their * OLD rangetable entries by the action below (in a recursive call of this * routine). */ rule_action = fireRIRrules(rule_action, activeRIRs, forUpdatePushedDown); /* * Now, plug the view query in as a subselect, replacing the relation's * original RTE. */ rte = rt_fetch(rt_index, parsetree->rtable); rte->rtekind = RTE_SUBQUERY; rte->relid = InvalidOid; rte->security_barrier = RelationIsSecurityView(relation); rte->subquery = rule_action; rte->inh = false; /* must not be set for a subquery */ /* * We move the view's permission check data down to its rangetable. The * checks will actually be done against the OLD entry therein. */ subrte = rt_fetch(PRS2_OLD_VARNO, rule_action->rtable); AssertEreport(subrte->relid == relation->rd_id, MOD_OPT, ""); subrte->requiredPerms = rte->requiredPerms; subrte->checkAsUser = rte->checkAsUser; subrte->selectedCols = rte->selectedCols; subrte->insertedCols = rte->insertedCols; subrte->updatedCols = rte->updatedCols; subrte->extraUpdatedCols = rte->extraUpdatedCols; rte->requiredPerms = 0; /* no permission check on subquery itself */ rte->checkAsUser = InvalidOid; rte->selectedCols = NULL; rte->insertedCols = NULL; rte->updatedCols = NULL; rte->extraUpdatedCols = NULL; /* * If FOR [KEY] UPDATE/SHARE of view, mark all the contained tables as implicit * FOR [KEY] UPDATE/SHARE, the same as the parser would have done if the view's * subquery had been written out explicitly. * * Note: we don't consider forUpdatePushedDown here; such marks will be * made by recursing from the upper level in markQueryForLocking. */ if (rc != NULL) markQueryForLocking(rule_action, (Node*)rule_action->jointree, rc->strength, rc->waitPolicy, true, rc->waitSec); return parsetree; } /* * Recursively mark all relations used by a view as FOR [KEY] UPDATE/SHARE. * * This may generate an invalid query, eg if some sub-query uses an * aggregate. We leave it to the planner to detect that. * * NB: this must agree with the parser's transformLockingClause() routine. * However, unlike the parser we have to be careful not to mark a view's * OLD and NEW rels for updating. The best way to handle that seems to be * to scan the jointree to determine which rels are used. */ static void markQueryForLocking(Query* qry, Node* jtnode, LockClauseStrength strength, LockWaitPolicy waitPolicy, bool pushedDown, int waitSec) { if (jtnode == NULL) return; if (IsA(jtnode, RangeTblRef)) { int rti = ((RangeTblRef*)jtnode)->rtindex; RangeTblEntry* rte = rt_fetch(rti, qry->rtable); if (rte->rtekind == RTE_RELATION) { applyLockingClause(qry, rti, strength, waitPolicy, pushedDown, waitSec); rte->requiredPerms |= ACL_SELECT_FOR_UPDATE; } else if (rte->rtekind == RTE_SUBQUERY) { applyLockingClause(qry, rti, strength, waitPolicy, pushedDown, waitSec); /* FOR UPDATE/SHARE of subquery is propagated to subquery's rels */ markQueryForLocking(rte->subquery, (Node*)rte->subquery->jointree, strength, waitPolicy, true, waitSec); } /* other RTE types are unaffected by FOR UPDATE */ } else if (IsA(jtnode, FromExpr)) { FromExpr* f = (FromExpr*)jtnode; ListCell* l = NULL; foreach (l, f->fromlist) markQueryForLocking(qry, (Node*)lfirst(l), strength, waitPolicy, pushedDown, waitSec); } else if (IsA(jtnode, JoinExpr)) { JoinExpr* j = (JoinExpr*)jtnode; markQueryForLocking(qry, j->larg, strength, waitPolicy, pushedDown, waitSec); markQueryForLocking(qry, j->rarg, strength, waitPolicy, pushedDown, waitSec); } else ereport(ERROR, (errmodule(MOD_OPT_REWRITE), errcode(ERRCODE_DATA_CORRUPTED), errmsg("unrecognized node type: %d", (int)nodeTag(jtnode)))); } /* * fireRIRonSubLink - * Apply fireRIRrules() to each SubLink (subselect in expression) found * in the given tree. * * NOTE: although this has the form of a walker, we cheat and modify the * SubLink nodes in-place. It is caller's responsibility to ensure that * no unwanted side-effects occur! * * This is unlike most of the other routines that recurse into subselects, * because we must take control at the SubLink node in order to replace * the SubLink's subselect link with the possibly-rewritten subquery. */ static bool fireRIRonSubLink(Node* node, List* activeRIRs) { if (node == NULL) return false; if (IsA(node, SubLink)) { SubLink* sub = (SubLink*)node; /* Do what we came for */ sub->subselect = (Node*)fireRIRrules((Query*)sub->subselect, activeRIRs, false); /* Fall through to process lefthand args of SubLink */ } /* * Do NOT recurse into Query nodes, because fireRIRrules already processed * subselects of subselects for us. */ return expression_tree_walker(node, (bool (*)())fireRIRonSubLink, (void*)activeRIRs); } /* * fireRIRrules - * Apply all RIR rules on each rangetable entry in a query */ static Query* fireRIRrules(Query* parsetree, List* activeRIRs, bool forUpdatePushedDown) { int origResultRelation = linitial2_int(parsetree->resultRelations); int rt_index; ListCell* lc = NULL; /* * don't try to convert this into a foreach loop, because rtable list can * get changed each time through... */ rt_index = 0; while (rt_index < list_length(parsetree->rtable)) { RangeTblEntry* rte = NULL; Relation rel; List* locks = NIL; RuleLock* rules = NULL; RewriteRule* rule = NULL; int i; ++rt_index; rte = rt_fetch(rt_index, parsetree->rtable); /* * A subquery RTE can't have associated rules, so there's nothing to * do to this level of the query, but we must recurse into the * subquery to expand any rule references in it. */ if (rte->rtekind == RTE_SUBQUERY) { rte->subquery = fireRIRrules( rte->subquery, activeRIRs, (forUpdatePushedDown || get_parse_rowmark(parsetree, rt_index) != NULL)); continue; } /* * Joins and other non-relation RTEs can be ignored completely. */ if (rte->rtekind != RTE_RELATION) { continue; } /* * Always ignore RIR rules for materialized views referenced in * queries. (This does not prevent refreshing MVs, since they aren't * referenced in their own query definitions.) * * Note: in the future we might want to allow MVs to be conditionally * expanded as if they were regular views, if they are not scannable. * In that case this test would need to be postponed till after we've * opened the rel, so that we could check its state. */ if (rte->relkind == RELKIND_MATVIEW) { continue; } /* * If the table is not referenced in the query, then we ignore it. * This prevents infinite expansion loop due to new rtable entries * inserted by expansion of a rule. A table is referenced if it is * part of the join set (a source table), or is referenced by any Var * nodes, or is the result table. */ if (rt_index != linitial2_int(parsetree->resultRelations) && !rangeTableEntry_used((Node*)parsetree, rt_index, 0)) { continue; } /* * Also, if this is a new result relation introduced by * ApplyRetrieveRule, we don't want to do anything more with it. */ if (rt_index == linitial2_int(parsetree->resultRelations) && rt_index != origResultRelation) { continue; } /* * We can use NoLock here since either the parser or * AcquireRewriteLocks should have locked the rel already. */ rel = heap_open(rte->relid, NoLock); /* * Collect the RIR rules that we must apply */ rules = rel->rd_rules; if (rules == NULL) { heap_close(rel, NoLock); continue; } for (i = 0; i < rules->numLocks; i++) { rule = rules->rules[i]; if (rule->event != CMD_SELECT) { continue; } if (rule->attrno > 0) { /* per-attr rule; do we need it? */ if (!attribute_used((Node*)parsetree, rt_index, rule->attrno, 0)) continue; } locks = lappend(locks, rule); } /* * If we found any, apply them --- but first check for recursion! */ if (locks != NIL) { ListCell* l = NULL; if (list_member_oid(activeRIRs, RelationGetRelid(rel))) { ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg( "infinite recursion detected in rules for relation \"%s\"", RelationGetRelationName(rel)))); } activeRIRs = lcons_oid(RelationGetRelid(rel), activeRIRs); foreach (l, locks) { rule = (RewriteRule*)lfirst(l); parsetree = ApplyRetrieveRule( parsetree, rule, rt_index, rule->attrno == -1, rel, activeRIRs, forUpdatePushedDown); } activeRIRs = list_delete_first(activeRIRs); } heap_close(rel, NoLock); } /* Recurse into subqueries in WITH */ foreach (lc, parsetree->cteList) { CommonTableExpr* cte = (CommonTableExpr*)lfirst(lc); cte->ctequery = (Node*)fireRIRrules((Query*)cte->ctequery, activeRIRs, false); } /* * Recurse into sublink subqueries, too. But we already did the ones in * the rtable and cteList. */ if (parsetree->hasSubLinks) { (void)query_tree_walker(parsetree, (bool (*)())fireRIRonSubLink, (void*)activeRIRs, QTW_IGNORE_RC_SUBQUERIES); } /* * Apply row level security policies. Do this work here because it * requires special recursion detection if the new quals have sublink * subqueries, and if we did it in the loop above query_tree_walker would * then recurse into those quals a second time. * Only bind R.L.S policies to plan on coordinator node like view. Currently * R.L.S only suport SELECT, UPDATE, DELETE. */ bool SupportRlsOnNode = true; #ifdef ENABLE_MULTIPLE_NODES SupportRlsOnNode = IS_PGXC_COORDINATOR; #endif if (SupportRlsOnNode && ((parsetree->commandType == CMD_SELECT) || (parsetree->commandType == CMD_UPDATE) || (parsetree->commandType == CMD_DELETE) || (parsetree->commandType == CMD_MERGE))) { rt_index = 0; foreach (lc, parsetree->rtable) { RangeTblEntry* rte = (RangeTblEntry*)lfirst(lc); List* securityQuals = NIL; bool hasRowSecurity = false; bool hasSubLink = false; rt_index++; /* Row-Level-Security policy can only applied to normal * relation(include partitioned relation) */ if ((rte->rtekind != RTE_RELATION) || (rte->relkind != RELKIND_RELATION)) { continue; } Relation targetTable = relation_open(rte->relid, NoLock); /* Fetch all R.L.S security quals that must be applied to this RTE */ GetRlsPolicies(parsetree, rte, targetTable, &securityQuals, rt_index, hasRowSecurity, hasSubLink); if (securityQuals != NIL) { /* * Add the new security barrier quals to the start of the RTE's * list so that they get applied before any existing barrier quals * (which would have come from a security-barrier view, and should * get lower priority than RLS conditions on the table itself). */ if (hasSubLink) { if (list_member_oid(activeRIRs, rte->relid)) { ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("infinite recursion detected, please check the row level security " "policies for relation \"%s\"", RelationGetRelationName(targetTable)))); } activeRIRs = lcons_oid(rte->relid, activeRIRs); /* * Get row level security policies just passed back securityQuals and * there were SubLink, make sure we lock any relations which are referenced. * These locks would normally be acquired by the parser, but securityQuals * are added post-parsing. */ (void)acquireLocksOnSubLinks((Node*)securityQuals, NULL); expression_tree_walker((Node*)securityQuals, (bool (*)())fireRIRonSubLink, (void*)activeRIRs); activeRIRs = list_delete_first(activeRIRs); parsetree->hasSubLinks = true; } rte->securityQuals = list_concat(securityQuals, rte->securityQuals); } /* For case CMD_MERGE, add securityQuals to MergeAction */ if (rt_index == linitial2_int(parsetree->resultRelations) && parsetree->commandType == CMD_MERGE && rte->securityQuals != NIL) { ListCell *lc = NULL; ListCell *next = NULL; Expr *security_quals_expr = (Expr *)lfirst(list_head(rte->securityQuals)); for (lc = lnext(list_head(rte->securityQuals)); lc != NULL; lc = next) { next = lnext(lc); List *lst = list_make2(security_quals_expr, lfirst(lc)); security_quals_expr = makeBoolExpr(AND_EXPR, lst, -1); } foreach (lc, parsetree->mergeActionList) { MergeAction *action = (MergeAction *)lfirst(lc); if (action->commandType == CMD_UPDATE) { if (action->qual == NULL) { action->qual = (Node *)security_quals_expr; } else { List *qual_list = list_make2(security_quals_expr, action->qual); action->qual = (Node *)makeBoolExpr(AND_EXPR, qual_list, -1); } rte->securityQuals = NIL; break; } } } /* Update Query hasRowSecurity */ parsetree->hasRowSecurity = (hasRowSecurity || parsetree->hasRowSecurity); relation_close(targetTable, NoLock); } } return parsetree; } /* * Modify the given query by adding 'AND rule_qual IS NOT TRUE' to its * qualification. This is used to generate suitable "else clauses" for * conditional INSTEAD rules. (Unfortunately we must use "x IS NOT TRUE", * not just "NOT x" which the planner is much smarter about, else we will * do the wrong thing when the qual evaluates to NULL.) * * The rule_qual may contain references to OLD or NEW. OLD references are * replaced by references to the specified rt_index (the relation that the * rule applies to). NEW references are only possible for INSERT and UPDATE * queries on the relation itself, and so they should be replaced by copies * of the related entries in the query's own targetlist. */ static Query* CopyAndAddInvertedQual(Query* parsetree, Node* rule_qual, int rt_index, CmdType event) { /* Don't scribble on the passed qual (it's in the relcache!) */ Node* new_qual = (Node*)copyObject(rule_qual); /* * In case there are subqueries in the qual, acquire necessary locks and * fix any deleted JOIN RTE entries. (This is somewhat redundant with * rewriteRuleAction, but not entirely ... consider restructuring so that * we only need to process the qual this way once.) */ (void)acquireLocksOnSubLinks(new_qual, NULL); /* Fix references to OLD */ ChangeVarNodes(new_qual, PRS2_OLD_VARNO, rt_index, 0); /* Fix references to NEW */ if (event == CMD_INSERT || event == CMD_UPDATE) new_qual = ResolveNew(new_qual, PRS2_NEW_VARNO, 0, rt_fetch(rt_index, parsetree->rtable), parsetree->targetList, event, rt_index, &parsetree->hasSubLinks); /* And attach the fixed qual */ AddInvertedQual(parsetree, new_qual); return parsetree; } /* * Generated column can not be manually insert or updated. */ static void CheckGeneratedColConstraint(CmdType commandType, Form_pg_attribute attTup, const TargetEntry *newTle) { if (commandType == CMD_INSERT) { ereport(ERROR, (errmodule(MOD_GEN_COL), errcode(ERRCODE_SYNTAX_ERROR), errmsg("cannot insert into column \"%s\"", NameStr(attTup->attname)), errdetail("Column \"%s\" is a generated column.", NameStr(attTup->attname)))); } else if (commandType == CMD_UPDATE && newTle) { ereport(ERROR, (errmodule(MOD_GEN_COL), errcode(ERRCODE_SYNTAX_ERROR), errmsg("column \"%s\" can only be updated to DEFAULT", NameStr(attTup->attname)), errdetail("Column \"%s\" is a generated column.", NameStr(attTup->attname)))); } } /* * very same to pg's rewriteTargetListIU. we adapt it to use for MergeInto */ static List* rewriteTargetListMergeInto( List* targetList, CmdType commandType, Relation target_relation, int result_rti, List** attrno_list) { TargetEntry** new_tles; List* new_tlist = NIL; List* junk_tlist = NIL; Form_pg_attribute att_tup; int attrno, next_junk_attrno, numattrs; ListCell* temp = NULL; if (attrno_list != NULL) /* initialize optional result list */ *attrno_list = NIL; /* * We process the normal (non-junk) attributes by scanning the input tlist * once and transferring TLEs into an array, then scanning the array to * build an output tlist. This avoids O(N^2) behavior for large numbers * of attributes. * * Junk attributes are tossed into a separate list during the same tlist * scan, then appended to the reconstructed tlist. */ numattrs = RelationGetNumberOfAttributes(target_relation); new_tles = (TargetEntry**)palloc0(numattrs * sizeof(TargetEntry*)); next_junk_attrno = numattrs + 1; foreach (temp, targetList) { TargetEntry* old_tle = (TargetEntry*)lfirst(temp); if (!old_tle->resjunk) { /* Normal attr: stash it into new_tles[] */ attrno = old_tle->resno; if (attrno < 1 || attrno > numattrs) { ereport(ERROR, (errcode(ERRCODE_AMBIGUOUS_COLUMN), errmsg("bogus resno %d in targetlist", attrno))); } att_tup = target_relation->rd_att->attrs[attrno - 1]; /* put attrno into attrno_list even if it's dropped */ if (attrno_list != NULL) *attrno_list = lappend_int(*attrno_list, attrno); /* We can (and must) ignore deleted attributes */ if (att_tup->attisdropped) continue; /* Merge with any prior assignment to same attribute */ new_tles[attrno - 1] = process_matched_tle(old_tle, new_tles[attrno - 1], NameStr(att_tup->attname)); } else { /* * Copy all resjunk tlist entries to junk_tlist, and assign them * resnos above the last real resno. * * Typical junk entries include ORDER BY or GROUP BY expressions * (are these actually possible in an INSERT or UPDATE?), system * attribute references, etc. */ /* Get the resno right, but don't copy unnecessarily */ if (old_tle->resno != next_junk_attrno) { old_tle = flatCopyTargetEntry(old_tle); old_tle->resno = next_junk_attrno; } junk_tlist = lappend(junk_tlist, old_tle); next_junk_attrno++; } } for (attrno = 1; attrno <= numattrs; attrno++) { TargetEntry* new_tle = new_tles[attrno - 1]; bool apply_default = false; att_tup = target_relation->rd_att->attrs[attrno - 1]; /* We can (and must) ignore deleted attributes */ if (att_tup->attisdropped) continue; /* * Handle the two cases where we need to insert a default expression: * it's an INSERT and there's no tlist entry for the column, or the * tlist entry is a DEFAULT placeholder node. */ apply_default = ((new_tle == NULL && commandType == CMD_INSERT) || (new_tle && new_tle->expr && IsA(new_tle->expr, SetToDefault))); bool isGeneratedCol = ISGENERATEDCOL(target_relation->rd_att, attrno - 1); if (isGeneratedCol) { if (!apply_default) { CheckGeneratedColConstraint(commandType, att_tup, new_tle); } /* * stored generated column will be fixed in executor */ new_tle = NULL; } else if (apply_default) { Node* new_expr = NULL; new_expr = build_column_default(target_relation, attrno, (commandType == CMD_INSERT)); /* * If there is no default (ie, default is effectively NULL), we * can omit the tlist entry in the INSERT case, since the planner * can insert a NULL for itself, and there's no point in spending * any more rewriter cycles on the entry. But in the UPDATE case * we've got to explicitly set the column to NULL. */ if (new_expr == NULL) { if (commandType == CMD_INSERT) new_tle = NULL; else { new_expr = (Node*)makeConst(att_tup->atttypid, -1, att_tup->attcollation, att_tup->attlen, (Datum)0, true, /* isnull */ att_tup->attbyval); /* this is to catch a NOT NULL domain constraint */ new_expr = coerce_to_domain( new_expr, InvalidOid, -1, att_tup->atttypid, COERCE_IMPLICIT_CAST, -1, false, false); } } if (new_expr != NULL) new_tle = makeTargetEntry((Expr*)new_expr, attrno, pstrdup(NameStr(att_tup->attname)), false); } if (new_tle != NULL) new_tlist = lappend(new_tlist, new_tle); } pfree_ext(new_tles); return list_concat(new_tlist, junk_tlist); } /* * fireRules - * Iterate through rule locks applying rules. * * Input arguments: * parsetree - original query * rt_index - RT index of result relation in original query * event - type of rule event * locks - list of rules to fire * Output arguments: * *instead_flag - set TRUE if any unqualified INSTEAD rule is found * (must be initialized to FALSE) * *returning_flag - set TRUE if we rewrite RETURNING clause in any rule * (must be initialized to FALSE) * *qual_product - filled with modified original query if any qualified * INSTEAD rule is found (must be initialized to NULL) * Return value: * list of rule actions adjusted for use with this query * * Qualified INSTEAD rules generate their action with the qualification * condition added. They also generate a modified version of the original * query with the negated qualification added, so that it will run only for * rows that the qualified action doesn't act on. (If there are multiple * qualified INSTEAD rules, we AND all the negated quals onto a single * modified original query.) We won't execute the original, unmodified * query if we find either qualified or unqualified INSTEAD rules. If * we find both, the modified original query is discarded too. */ static List* fireRules(Query* parsetree, int rt_index, CmdType event, List* locks, bool* instead_flag, bool* returning_flag, Query** qual_product) { List* results = NIL; ListCell* l = NULL; foreach (l, locks) { RewriteRule* rule_lock = (RewriteRule*)lfirst(l); Node* event_qual = rule_lock->qual; List* actions = rule_lock->actions; QuerySource qsrc; ListCell* r = NULL; /* Determine correct QuerySource value for actions */ if (rule_lock->isInstead) { if (event_qual != NULL) qsrc = QSRC_QUAL_INSTEAD_RULE; else { qsrc = QSRC_INSTEAD_RULE; *instead_flag = true; /* report unqualified INSTEAD */ } } else qsrc = QSRC_NON_INSTEAD_RULE; if (qsrc == QSRC_QUAL_INSTEAD_RULE) { /* * If there are INSTEAD rules with qualifications, the original * query is still performed. But all the negated rule * qualifications of the INSTEAD rules are added so it does its * actions only in cases where the rule quals of all INSTEAD rules * are false. Think of it as the default action in a case. We save * this in *qual_product so RewriteQuery() can add it to the query * list after we mangled it up enough. * * If we have already found an unqualified INSTEAD rule, then * *qual_product won't be used, so don't bother building it. */ if (!*instead_flag) { if (*qual_product == NULL) *qual_product = (Query*)copyObject(parsetree); *qual_product = CopyAndAddInvertedQual(*qual_product, event_qual, rt_index, event); } } /* Now process the rule's actions and add them to the result list */ foreach (r, actions) { Query* rule_action = (Query*)lfirst(r); if (rule_action->commandType == CMD_NOTHING) continue; rule_action = rewriteRuleAction(parsetree, rule_action, event_qual, rt_index, event, returning_flag); rule_action->querySource = qsrc; rule_action->canSetTag = false; /* might change later */ results = lappend(results, rule_action); } } return results; } void ereport_for_each_cmdtype(CmdType event, Relation rt_entry_relation) { switch (event) { case CMD_INSERT: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot perform INSERT RETURNING on relation \"%s\"", RelationGetRelationName(rt_entry_relation)), errhint("You need an unconditional ON INSERT DO INSTEAD rule with a RETURNING clause."))); break; case CMD_UPDATE: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot perform UPDATE RETURNING on relation \"%s\"", RelationGetRelationName(rt_entry_relation)), errhint("You need an unconditional ON UPDATE DO INSTEAD rule with a RETURNING clause."))); break; case CMD_DELETE: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot perform DELETE RETURNING on relation \"%s\"", RelationGetRelationName(rt_entry_relation)), errhint("You need an unconditional ON DELETE DO INSTEAD rule with a RETURNING clause."))); break; default: { ereport( ERROR, (errcode(ERRCODE_UNEXPECTED_NODE_STATE), errmsg("unrecognized commandType: %d", (int)event))); } break; } } /* * RewriteQuery - * rewrites the query and apply the rules again on the queries rewritten * * rewrite_events is a list of open query-rewrite actions, so we can detect * infinite recursion. */ static List* RewriteQuery(Query* parsetree, List* rewrite_events) { CmdType event = parsetree->commandType; bool instead = false; bool returning = false; Query* qual_product = NULL; List* rewritten = NIL; ListCell* lc1 = NULL; #ifdef PGXC List* parsetree_list = NIL; List* qual_product_list = NIL; ListCell* pt_cell = NULL; #endif /* * First, recursively process any insert/update/delete statements in WITH * clauses. (We have to do this first because the WITH clauses may get * copied into rule actions below.) */ foreach (lc1, parsetree->cteList) { CommonTableExpr* cte = (CommonTableExpr*)lfirst(lc1); Query* ctequery = (Query*)cte->ctequery; List* newstuff = NIL; AssertEreport(IsA(ctequery, Query), MOD_OPT, ""); if (ctequery->commandType == CMD_SELECT) continue; newstuff = RewriteQuery(ctequery, rewrite_events); /* * Currently we can only handle unconditional, single-statement DO * INSTEAD rules correctly; we have to get exactly one Query out of * the rewrite operation to stuff back into the CTE node. */ if (list_length(newstuff) == 1) { /* Push the single Query back into the CTE node */ ctequery = (Query*)linitial(newstuff); AssertEreport(IsA(ctequery, Query), MOD_OPT, ""); /* WITH queries should never be canSetTag */ AssertEreport(!ctequery->canSetTag, MOD_OPT, ""); cte->ctequery = (Node*)ctequery; } else if (newstuff == NIL) { ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("DO INSTEAD NOTHING rules are not supported for data-modifying statements in WITH"))); } else { ListCell* lc2 = NULL; /* examine queries to determine which error message to issue */ foreach (lc2, newstuff) { Query* q = (Query*)lfirst(lc2); if (q->querySource == QSRC_QUAL_INSTEAD_RULE) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("conditional DO INSTEAD rules are not supported for data-modifying statements in " "WITH"))); if (q->querySource == QSRC_NON_INSTEAD_RULE) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("DO ALSO rules are not supported for data-modifying statements in WITH"))); } ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg( "multi-statement DO INSTEAD rules are not supported for data-modifying statements in WITH"))); } } /* * If the statement is an insert, update, or delete, adjust its targetlist * as needed, and then fire INSERT/UPDATE/DELETE rules on it. * * SELECT rules are handled later when we have all the queries that should * get executed. Also, utilities aren't rewritten at all (do we still * need that check?) */ if (event != CMD_SELECT && event != CMD_UTILITY) { int result_relation; RangeTblEntry* rt_entry = NULL; Relation rt_entry_relation; List* locks = NIL; bool hasGenCol = false; result_relation = linitial_int(parsetree->resultRelations); if (result_relation == 0) return rewritten; rt_entry = rt_fetch(result_relation, parsetree->rtable); AssertEreport(rt_entry->rtekind == RTE_RELATION, MOD_OPT, ""); /* * We can use NoLock here since either the parser or * AcquireRewriteLocks should have locked the rel already. */ rt_entry_relation = heap_open(rt_entry->relid, NoLock); /* * Rewrite the targetlist as needed for the command type. */ if (event == CMD_INSERT) { RangeTblEntry* values_rte = NULL; /* * If it's an INSERT ... VALUES (...), (...), ... there will be a * single RTE for the VALUES targetlists. */ if (list_length(parsetree->jointree->fromlist) == 1) { RangeTblRef* rtr = (RangeTblRef*)linitial(parsetree->jointree->fromlist); if (IsA(rtr, RangeTblRef)) { RangeTblEntry* rte = rt_fetch(rtr->rtindex, parsetree->rtable); if (rte->rtekind == RTE_VALUES) values_rte = rte; } } if (values_rte != NULL) { List* attrnos = NIL; /* Process the main targetlist ... */ parsetree->targetList = rewriteTargetListIU(parsetree->targetList, parsetree->commandType, rt_entry_relation, result_relation, &attrnos, &hasGenCol); checkGenDefault(values_rte, rt_entry_relation, attrnos, hasGenCol); /* ... and the VALUES expression lists */ rewriteValuesRTE(values_rte, rt_entry_relation, attrnos); } else { /* Process just the main targetlist */ parsetree->targetList = rewriteTargetListIU(parsetree->targetList, parsetree->commandType, rt_entry_relation, result_relation, NULL, &hasGenCol); } if (parsetree->upsertClause != NULL && parsetree->upsertClause->upsertAction == UPSERT_UPDATE) { parsetree->upsertClause->updateTlist = rewriteTargetListIU(parsetree->upsertClause->updateTlist, CMD_UPDATE, rt_entry_relation, result_relation, NULL, &hasGenCol); } } else if (event == CMD_UPDATE) { if (list_length(parsetree->resultRelations) > 1) { rewriteTargetListMutilUpdate(parsetree, parsetree->rtable, parsetree->resultRelations); } else { parsetree->targetList = rewriteTargetListIU(parsetree->targetList, parsetree->commandType, rt_entry_relation, result_relation, NULL, &hasGenCol); rewriteTargetListUD(parsetree, rt_entry, rt_entry_relation, result_relation); } } else if (event == CMD_DELETE) { if (list_length(parsetree->resultRelations) > 1) { rewriteTargetListMutilUD(parsetree, parsetree->rtable, parsetree->resultRelations); } else { rewriteTargetListUD(parsetree, rt_entry, rt_entry_relation, result_relation); } } else if (event == CMD_MERGE) { /* * Rewrite each action targetlist separately */ foreach (lc1, parsetree->mergeActionList) { MergeAction* action = (MergeAction*)lfirst(lc1); switch (action->commandType) { case CMD_DELETE: /* Nothing to do here */ break; case CMD_UPDATE: action->targetList = rewriteTargetListMergeInto(action->targetList, action->commandType, rt_entry_relation, result_relation, NULL); break; case CMD_INSERT: { action->targetList = rewriteTargetListMergeInto(action->targetList, action->commandType, rt_entry_relation, result_relation, NULL); } break; default: { ereport(ERROR, (errcode(ERRCODE_UNEXPECTED_NODE_STATE), errmsg("unrecognized commandType: %d", action->commandType))); } break; } } if (parsetree->upsertQuery != NULL) { List* querytree_list = QueryRewrite(parsetree->upsertQuery); if (list_length(querytree_list) != 1) { ereport(ERROR, (errcode(ERRCODE_INVALID_STATUS ), errmsg("Unexpected status in upsert to merge."))); } parsetree->upsertQuery = (Query*)linitial(querytree_list); } } else { ereport(ERROR, (errcode(ERRCODE_INVALID_OPERATION), errmsg("unrecognized commandType: %d", (int)event))); } #ifdef PGXC if (parsetree_list == NIL) { #endif /* * Collect and apply the appropriate rules. */ locks = matchLocks(event, rt_entry_relation->rd_rules, result_relation, parsetree); if (locks != NIL) { List* product_queries = NIL; #ifdef ENABLE_MULTIPLE_NODES if (IS_PGXC_COORDINATOR) { product_queries = fireRules(parsetree, result_relation, event, locks, &instead, &returning, &qual_product); } #else product_queries = fireRules(parsetree, result_relation, event, locks, &instead, &returning, &qual_product); #endif /* * If we got any product queries, recursively rewrite them --- but * first check for recursion! */ if (product_queries != NIL) { ListCell* n = NULL; rewrite_event* rev = NULL; foreach (n, rewrite_events) { rev = (rewrite_event*)lfirst(n); if (rev->relation == RelationGetRelid(rt_entry_relation) && rev->event == event) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("infinite recursion detected in rules for relation \"%s\"", RelationGetRelationName(rt_entry_relation)))); } rev = (rewrite_event*)palloc(sizeof(rewrite_event)); rev->relation = RelationGetRelid(rt_entry_relation); rev->event = event; rewrite_events = lcons(rev, rewrite_events); foreach (n, product_queries) { Query* pt = (Query*)lfirst(n); List* newstuff = NULL; newstuff = RewriteQuery(pt, rewrite_events); rewritten = list_concat(rewritten, newstuff); } rewrite_events = list_delete_first(rewrite_events); } } /* * If there is an INSTEAD, and the original query has a RETURNING, we * have to have found a RETURNING in the rule(s), else fail. (Because * DefineQueryRewrite only allows RETURNING in unconditional INSTEAD * rules, there's no need to worry whether the substituted RETURNING * will actually be executed --- it must be.) */ if ((instead || qual_product != NULL) && parsetree->returningList && !returning) { ereport_for_each_cmdtype(event, rt_entry_relation); } heap_close(rt_entry_relation, NoLock); #ifdef PGXC } else { foreach (pt_cell, parsetree_list) { Query* query = NULL; query = (Query*)lfirst(pt_cell); /* * Collect and apply the appropriate rules. */ locks = matchLocks(event, rt_entry_relation->rd_rules, result_relation, query); if (locks != NIL) { List* product_queries = NIL; if (IS_PGXC_COORDINATOR) product_queries = fireRules(query, result_relation, event, locks, &instead, &returning, &qual_product); qual_product_list = lappend(qual_product_list, qual_product); /* * If we got any product queries, recursively rewrite them --- but * first check for recursion! */ if (product_queries != NIL) { ListCell* n = NULL; rewrite_event* rev = NULL; foreach (n, rewrite_events) { rev = (rewrite_event*)lfirst(n); if (rev->relation == RelationGetRelid(rt_entry_relation) && rev->event == event) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("infinite recursion detected in rules for relation \"%s\"", RelationGetRelationName(rt_entry_relation)))); } rev = (rewrite_event*)palloc(sizeof(rewrite_event)); rev->relation = RelationGetRelid(rt_entry_relation); rev->event = event; rewrite_events = lcons(rev, rewrite_events); foreach (n, product_queries) { Query* pt = (Query*)lfirst(n); List* newstuff = NIL; newstuff = RewriteQuery(pt, rewrite_events); rewritten = list_concat(rewritten, newstuff); } rewrite_events = list_delete_first(rewrite_events); } } /* * If there is an INSTEAD, and the original query has a RETURNING, we * have to have found a RETURNING in the rule(s), else fail. (Because * DefineQueryRewrite only allows RETURNING in unconditional INSTEAD * rules, there's no need to worry whether the substituted RETURNING * will actually be executed --- it must be.) */ if ((instead || qual_product != NULL) && query->returningList && !returning) { ereport_for_each_cmdtype(event, rt_entry_relation); } } heap_close(rt_entry_relation, NoLock); } } if (parsetree_list == NIL) { #endif /* * For INSERTs, the original query is done first; for UPDATE/DELETE, it is * done last. This is needed because update and delete rule actions might * not do anything if they are invoked after the update or delete is * performed. The command counter increment between the query executions * makes the deleted (and maybe the updated) tuples disappear so the scans * for them in the rule actions cannot find them. * * If we found any unqualified INSTEAD, the original query is not done at * all, in any form. Otherwise, we add the modified form if qualified * INSTEADs were found, else the unmodified form. */ if (!instead) { if (parsetree->commandType == CMD_INSERT) { if (qual_product != NULL) rewritten = lcons(qual_product, rewritten); else rewritten = lcons(parsetree, rewritten); } else { if (qual_product != NULL) rewritten = lappend(rewritten, qual_product); else rewritten = lappend(rewritten, parsetree); } } #ifdef PGXC } else { int query_no = 0; foreach (pt_cell, parsetree_list) { Query* query = NULL; Query* qual = NULL; query = (Query*)lfirst(pt_cell); if (instead == false) { if (qual_product_list != NIL) qual = (Query*)list_nth(qual_product_list, query_no); if (query->commandType == CMD_INSERT) { if (qual != NULL) rewritten = lcons(qual, rewritten); else rewritten = lcons(query, rewritten); } else { if (qual != NULL) rewritten = lappend(rewritten, qual); else rewritten = lappend(rewritten, query); } } query_no++; } } #endif /* * If the original query has a CTE list, and we generated more than one * non-utility result query, we have to fail because we'll have copied the * CTE list into each result query. That would break the expectation of * single evaluation of CTEs. This could possibly be fixed by * restructuring so that a CTE list can be shared across multiple Query * and PlannableStatement nodes. */ if (parsetree->cteList != NIL) { int qcount = 0; foreach (lc1, rewritten) { Query* q = (Query*)lfirst(lc1); if (q->commandType != CMD_UTILITY) qcount++; } if (qcount > 1) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("WITH cannot be used in a query that is rewritten by rules into multiple queries"))); } return rewritten; } /* * QueryRewrite - * Primary entry point to the query rewriter. * Rewrite one query via query rewrite system, possibly returning 0 * or many queries. * * NOTE: the parsetree must either have come straight from the parser, * or have been scanned by AcquireRewriteLocks to acquire suitable locks. */ List* QueryRewrite(Query* parsetree) { uint64 input_query_id = parsetree->queryId; List* querylist = NIL; List* results = NIL; ListCell* l = NULL; CmdType origCmdType; bool foundOriginalQuery = false; Query* lastInstead = NULL; /* * This function is only applied to top-level original queries */ AssertEreport(parsetree->querySource == QSRC_ORIGINAL, MOD_OPT, ""); AssertEreport(parsetree->canSetTag, MOD_OPT, ""); /* * Step 1 * * Apply all non-SELECT rules possibly getting 0 or many queries */ querylist = RewriteQuery(parsetree, NIL); /* * Step 2 * * Apply all the RIR rules on each query * * This is also a handy place to mark each query with the original queryId */ results = NIL; foreach (l, querylist) { Query* query = (Query*)lfirst(l); query = fireRIRrules(query, NIL, false); query->queryId = input_query_id; results = lappend(results, query); } /* * Step 3 * * Determine which, if any, of the resulting queries is supposed to set * the command-result tag; and update the canSetTag fields accordingly. * * If the original query is still in the list, it sets the command tag. * Otherwise, the last INSTEAD query of the same kind as the original is * allowed to set the tag. (Note these rules can leave us with no query * setting the tag. The tcop code has to cope with this by setting up a * default tag based on the original un-rewritten query.) * * The Asserts verify that at most one query in the result list is marked * canSetTag. If we aren't checking asserts, we can fall out of the loop * as soon as we find the original query. */ origCmdType = parsetree->commandType; foundOriginalQuery = false; lastInstead = NULL; foreach (l, results) { Query* query = (Query*)lfirst(l); if (query->querySource == QSRC_ORIGINAL) { AssertEreport(query->canSetTag, MOD_OPT, ""); #ifndef PGXC AssertEreport(!foundOriginalQuery, MOD_OPT, ""); #endif foundOriginalQuery = true; #ifndef USE_ASSERT_CHECKING break; #endif } else { AssertEreport(!query->canSetTag, MOD_OPT, ""); if (query->commandType == origCmdType && (query->querySource == QSRC_INSTEAD_RULE || query->querySource == QSRC_QUAL_INSTEAD_RULE)) lastInstead = query; } } if (!foundOriginalQuery && lastInstead != NULL) lastInstead->canSetTag = true; if (CONVERT_STRING_DIGIT_TO_NUMERIC) { foreach (l, results) { (void)PreprocessOperator((Node*)lfirst(l), NULL); } } return results; } #ifdef PGXC char* GetCreateViewStmt(Query* parsetree, CreateTableAsStmt* stmt) { /* Obtain the target list of new table */ AssertEreport(IsA(stmt->query, Query), MOD_OPT, ""); ViewStmt* view_stmt = makeNode(ViewStmt); view_stmt->view = stmt->into->rel; view_stmt->query = stmt->query; view_stmt->view->relpersistence = RELPERSISTENCE_PERMANENT; view_stmt->aliases = stmt->into->colNames; view_stmt->options = stmt->into->options; view_stmt->relkind = OBJECT_MATVIEW; view_stmt->ivm = stmt->into->ivm; #ifdef ENABLE_MULTIPLE_NODES PGXCSubCluster* subcluster = NULL; if (stmt->into->subcluster == NULL && view_stmt->ivm) { char *group_name = ng_get_group_group_name(stmt->groupid); subcluster = makeNode(PGXCSubCluster); subcluster->clustertype = SUBCLUSTER_GROUP; subcluster->members = list_make1(makeString(group_name)); view_stmt->subcluster = subcluster; stmt->into->subcluster = subcluster; } else { view_stmt->subcluster = stmt->into->subcluster; } #endif parsetree->commandType = CMD_UTILITY; parsetree->utilityStmt = (Node*)view_stmt; StringInfo cquery = makeStringInfo(); deparse_query(parsetree, cquery, NIL, false, false); return cquery->data; } char* GetCreateTableStmt(Query* parsetree, CreateTableAsStmt* stmt) { /* Start building a CreateStmt for creating the target table */ CreateStmt* create_stmt = makeNode(CreateStmt); create_stmt->relation = stmt->into->rel; IntoClause* into = stmt->into; List* tableElts = NIL; /* Obtain the target list of new table */ AssertEreport(IsA(stmt->query, Query), MOD_OPT, ""); Query* cparsetree = (Query*)stmt->query; List* tlist = cparsetree->targetList; /* * Based on the targetList, populate the column information for the target * table. If a column name list was specified in CREATE TABLE AS, override * the column names derived from the query. (Too few column names are OK, too * many are not.). */ ListCell* col = NULL; ListCell* lc = list_head(into->colNames); foreach (col, tlist) { TargetEntry* tle = (TargetEntry*)lfirst(col); ColumnDef* coldef = NULL; ClientLogicColumnRef *coldef_enc = NULL; TypeName* tpname = NULL; if (IsA(tle->expr, Var)) { Var* ColTypProperty = (Var*)(tle->expr); /* * It's possible that the column is of a collatable type but the * collation could not be resolved, so double-check. (We must check * this here because DefineRelation would adopt the type's default * collation rather than complaining.) */ if (!OidIsValid(ColTypProperty->varcollid) && type_is_collatable(ColTypProperty->vartype)) ereport(ERROR, (errcode(ERRCODE_INDETERMINATE_COLLATION), errmsg("no collation was derived for column \"%s\" with collatable type %s", tle->resname, format_type_be(ColTypProperty->vartype)), errhint("Use the COLLATE clause to set the collation explicitly."))); } /* Ignore junk columns from the targetlist */ if (tle->resjunk) continue; coldef = makeNode(ColumnDef); tpname = makeNode(TypeName); /* Take the column name specified if any */ if (lc != NULL) { coldef->colname = strVal(lfirst(lc)); lc = lnext(lc); } else coldef->colname = pstrdup(tle->resname); coldef->inhcount = 0; coldef->is_local = true; coldef->is_not_null = false; /* The best way to set cmprs_mode is copied from the source column defination. * but the cost is heavy, so make it the default method without forbiting compressing. * refer to ExecCreateTableAs() --> CreateIntoRelDestReceiver() --> intorel_startup() */ coldef->cmprs_mode = ATT_CMPR_UNDEFINED; coldef->raw_default = NULL; coldef->cooked_default = NULL; coldef->update_default = NULL; coldef->constraints = NIL; /* * Set typeOid and typemod. The name of the type is derived while * generating query */ tpname->typeOid = exprType((Node*)tle->expr); tpname->typemod = exprTypmod((Node*)tle->expr); /* * If the column of source relation is encrypted * instead of copying its typeOid directly * we should get its original defination from the catalog */ if (is_enc_type(tpname->typeOid)) { coldef_enc = get_column_enc_def(tle->resorigtbl, tle->resname); if (coldef_enc != NULL) { /* should never be NULL */ coldef_enc->dest_typname = makeTypeNameFromOid(tpname->typeOid, -1); tpname->typeOid = coldef_enc->orig_typname->typeOid; tpname->typemod = coldef_enc->orig_typname->typemod; } coldef->clientLogicColumnRef = coldef_enc; } coldef->typname = tpname; tableElts = lappend(tableElts, coldef); } if (lc != NULL) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("%s specifies too many column names", stmt->relkind == OBJECT_MATVIEW ? "CREATE MATERIALIZED VIEW" : "CREATE TABLE AS"))); /* * Set column information and the distribution mechanism (which will be * NULL for SELECT INTO and the default mechanism will be picked) */ create_stmt->tableElts = tableElts; create_stmt->distributeby = stmt->into->distributeby; create_stmt->subcluster = stmt->into->subcluster; create_stmt->tablespacename = stmt->into->tableSpaceName; create_stmt->oncommit = stmt->into->onCommit; create_stmt->row_compress = stmt->into->row_compress; create_stmt->options = stmt->into->options; create_stmt->ivm = stmt->into->ivm; create_stmt->relkind = stmt->relkind == OBJECT_MATVIEW ? RELKIND_MATVIEW : RELKIND_RELATION; /* * Check consistency of arguments */ if (create_stmt->oncommit != ONCOMMIT_NOOP && create_stmt->relation->relpersistence != RELPERSISTENCE_TEMP && create_stmt->relation->relpersistence != RELPERSISTENCE_GLOBAL_TEMP) { ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("ON COMMIT can only be used on temporary tables"))); } #ifdef ENABLE_MULTIPLE_NODES if (create_stmt->subcluster == NULL && create_stmt->relkind == RELKIND_MATVIEW && create_stmt->ivm) { PGXCSubCluster* subcluster = NULL; char *group_name = ng_get_group_group_name(stmt->groupid); subcluster = makeNode(PGXCSubCluster); subcluster->clustertype = SUBCLUSTER_GROUP; subcluster->members = list_make1(makeString(group_name)); create_stmt->subcluster = subcluster; stmt->into->subcluster = subcluster; } #endif /* * Now build a utility statement in order to run the CREATE TABLE DDL on * the local and remote nodes. We keep others fields as it is since they * are ignored anyways by deparse_query. */ parsetree->commandType = CMD_UTILITY; parsetree->utilityStmt = (Node*)create_stmt; StringInfo cquery = makeStringInfo(); deparse_query(parsetree, cquery, NIL, false, false); return cquery->data; } static bool selectNeedRecovery(Query* query) { if (!query->hasRecursive || query->sql_statement == NULL) { return false; } return strcasestr(query->sql_statement, "CONNECT") != NULL; } char* GetInsertIntoStmt(CreateTableAsStmt* stmt) { /* Get the SELECT query string */ /* * If target table name is the same as an existed one and schema name is NULL, INSERT INTO * statement may not find the right target table. Therefore we should get the schema name * first so that the INSERT INTO statement can insert into the target table. */ RangeVar *relation = stmt->into->rel; if (relation->schemaname == NULL && relation->relpersistence != RELPERSISTENCE_TEMP) { Oid namespaceid = RangeVarGetAndCheckCreationNamespace(relation, NoLock, NULL, RELKIND_RELATION); relation->schemaname = get_namespace_name(namespaceid); } StringInfo cquery = makeStringInfo(); deparse_query((Query*)stmt->query, cquery, NIL, false, false, stmt->parserSetupArg); char* selectstr = pstrdup(cquery->data); /* * Check if we should recover from the rewriting performed on the select part, * e.g. for START WITH cases we need to do this after rewriting */ Query* select_query = (Query*)stmt->query; if (selectNeedRecovery(select_query)) { selectstr = pstrdup(select_query->sql_statement); } /* Now, finally build the INSERT INTO statement */ initStringInfo(cquery); appendStringInfo(cquery, "INSERT "); HintState *hintState = ((Query*)stmt->query)->hintState; get_hint_string(hintState, cquery); if (relation->schemaname) appendStringInfo( cquery, " INTO %s.%s", quote_identifier(relation->schemaname), quote_identifier(relation->relname)); else appendStringInfo(cquery, " INTO %s", quote_identifier(relation->relname)); /* * If the original sql contains "WITH NO DATA", just create * the table without inserting any data. */ if (stmt->into->skipData) appendStringInfoString(cquery, " select null where false"); else appendStringInfo(cquery, " %s", selectstr); return cquery->data; } List *query_rewrite_multiset_stmt(Query *query) { List* querytree_list = NIL; VariableMultiSetStmt* muti_stmt = (VariableMultiSetStmt*)query->utilityStmt; List* stmts = muti_stmt->args; ListCell* cell = NULL; VariableSetStmt *set_stmt; foreach(cell, stmts) { Node* stmt = (Node*)lfirst(cell); if (nodeTag(stmt) == T_AlterSystemStmt) { AlterSystemStmt* alter_sys_stmt = (AlterSystemStmt *)stmt; set_stmt = alter_sys_stmt->setstmt; } else { set_stmt = (VariableSetStmt*)stmt; } if (list_length(set_stmt->args) > 1) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("set %s takes only one argument", set_stmt->name))); } if(set_stmt->kind == VAR_SET_VALUE) { List *resultlist = NIL; ListCell *l = NULL; foreach(l, set_stmt->args) { Node* expr = (Node*)lfirst(l); Node* node = NULL; if(IsA(expr, A_Const)) { node = expr; } else { node = eval_const_expression_value(NULL, expr, NULL); if(nodeTag(node) != T_Const) { node = QueryRewriteNonConstant(expr); } node = transferConstToAconst(node); } resultlist = lappend(resultlist, (A_Const*)node); } list_free(set_stmt->args); set_stmt->args = resultlist; } } querytree_list = list_make1(query); return querytree_list; } List *query_rewrite_set_stmt(Query *query) { List* querytree_list = NIL; VariableSetStmt *stmt = (VariableSetStmt *)query->utilityStmt; if(DB_IS_CMPT(B_FORMAT) && stmt->kind == VAR_SET_VALUE && u_sess->attr.attr_common.enable_set_variable_b_format) { List *resultlist = NIL; ListCell *l = NULL; foreach(l, stmt->args) { Node* expr = (Node*)lfirst(l); Node* node = NULL; if(nodeTag(expr) == T_A_Const) { node = expr; } else { node = eval_const_expression_value(NULL, expr, NULL); if(nodeTag(node) != T_Const) { node = QueryRewriteNonConstant(expr); } node = transferConstToAconst(node); } resultlist = lappend(resultlist, (A_Const*)node); } list_free(stmt->args); stmt->args = resultlist; } querytree_list = list_make1(query); return querytree_list; } List *QueryRewriteRefresh(Query *parse_tree) { RefreshMatViewStmt* stmt = NULL; RewriteRule *rule = NULL; Oid matviewOid; Relation matviewRel; List *actions = NIL; Query *dataQuery; List* raw_parsetree_list = NIL; if (parse_tree->commandType != CMD_UTILITY || !IsA(parse_tree->utilityStmt, RefreshMatViewStmt)) { ereport(ERROR, (errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("Unexpected commandType or intoClause is not set properly"))); } /* Get the target table */ stmt = (RefreshMatViewStmt *)parse_tree->utilityStmt; RangeVar *relation = stmt->relation; if (relation->schemaname == NULL && relation->relpersistence != RELPERSISTENCE_TEMP) { Oid namespaceid = RangeVarGetAndCheckCreationNamespace(relation, NoLock, NULL, RELKIND_MATVIEW); relation->schemaname = get_namespace_name(namespaceid); } StringInfo tquery = makeStringInfo(); /* 1. TRUNCATE mv */ initStringInfo(tquery); if (IS_PGXC_COORDINATOR) { appendStringInfo(tquery, "REFRESH MATERIALIZED VIEW "); } else { appendStringInfo(tquery, "TRUNCATE TABLE "); } if (relation->schemaname) appendStringInfo( tquery, "%s.%s", quote_identifier(relation->schemaname), quote_identifier(relation->relname)); else appendStringInfo(tquery, "%s", quote_identifier(relation->relname)); char *refresh_sql = tquery->data; if (IS_PGXC_COORDINATOR) { ExecUtilityStmtOnNodes(refresh_sql, NULL, false, false, EXEC_ON_DATANODES, false); } else { raw_parsetree_list = pg_parse_query(refresh_sql); return pg_analyze_and_rewrite((Node*)linitial(raw_parsetree_list), refresh_sql, NULL, 0); } /* 2. Insert Into .... Select statement */ StringInfo cquery = makeStringInfo(); /* * Get a lock until end of transaction. */ matviewOid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock, false, false, false, false, RangeVarCallbackOwnsTable, NULL); matviewRel = heap_open(matviewOid, NoLock); /* Make sure it is a materialized view. */ if (matviewRel->rd_rel->relkind != RELKIND_MATVIEW) { ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("\"%s\" is not a materialized view", RelationGetRelationName(matviewRel)))); } if (IS_PGXC_COORDINATOR) { CheckRefreshMatview(matviewRel, false); } rule = matviewRel->rd_rules->rules[0]; actions = rule->actions; if (list_length(actions) != 1) { ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("the rule for materialized view \"%s\" is not a single action", RelationGetRelationName(matviewRel)))); } dataQuery = (Query *) linitial(actions); Query* parsetree = (Query*)copyObject(dataQuery); deparse_query(parsetree, cquery, NIL, false, false, NULL); char* selectstr = pstrdup(cquery->data); pfree_ext(parsetree); initStringInfo(cquery); appendStringInfo(cquery, "INSERT "); HintState *hintState = dataQuery->hintState; if (hintState != NULL && hintState->multi_node_hint) { appendStringInfo(cquery, " /*+ multinode */ "); } if (hintState != NULL && hintState->sql_ignore_hint) { appendStringInfo(cquery, " /*+ ignore_error */ "); } if (relation->schemaname) { appendStringInfo(cquery, " INTO %s.%s", quote_identifier(relation->schemaname), quote_identifier(relation->relname)); } else { appendStringInfo(cquery, " INTO %s", quote_identifier(relation->relname)); } appendStringInfo(cquery, " %s", selectstr); char *insert_select_sql = cquery->data; raw_parsetree_list = pg_parse_query(insert_select_sql); heap_close(matviewRel, NoLock); Assert(IsA(linitial(raw_parsetree_list), InsertStmt)); linitial_node(InsertStmt, raw_parsetree_list)->isRewritten = true; return pg_analyze_and_rewrite((Node*)linitial(raw_parsetree_list), insert_select_sql, NULL, 0); } /* * Rewrite the CREATE TABLE AS and SELECT INTO queries as a * INSERT INTO .. SELECT query. The target table must be created first using * utility command processing. This takes care of creating the target table on * all the Coordinators and the Datanodes. */ List* QueryRewriteCTAS(Query* parsetree) { List* raw_parsetree_list = NIL; CreateTableAsStmt* stmt = NULL; Query* zparsetree = NULL; char* view_sql = NULL; if (parsetree->commandType != CMD_UTILITY || !IsA(parsetree->utilityStmt, CreateTableAsStmt)) { ereport(ERROR, (errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("Unexpected commandType or intoClause is not set properly"))); } /* Get the target table */ stmt = (CreateTableAsStmt*)parsetree->utilityStmt; /* CREATE TABLE AS */ Query* cparsetree = (Query*)copyObject(parsetree); char* create_sql = GetCreateTableStmt(cparsetree, stmt); if (stmt->relkind == OBJECT_MATVIEW) { zparsetree = (Query*)copyObject(cparsetree); view_sql = GetCreateViewStmt(zparsetree, stmt); ViewStmt *mvStmt = (ViewStmt *)zparsetree->utilityStmt; mvStmt->mv_stmt = cparsetree->utilityStmt; mvStmt->mv_sql = create_sql; } /* If MATILIZED VIEW exists, cannot send create table to DNs. */ if (stmt->relkind != OBJECT_MATVIEW) { ProcessUtility(cparsetree->utilityStmt, create_sql, NULL, true, NULL, false, NULL); } /* CREATE MATILIZED VIEW AS*/ if (stmt->relkind == OBJECT_MATVIEW) { Query *query = (Query *)stmt->query; ProcessUtility(zparsetree->utilityStmt, view_sql, NULL, true, NULL, false, NULL); create_matview_meta(query, stmt->into->rel, stmt->into->ivm); /* for ivm should not execute insert into ... select just return. */ if (stmt->into->ivm) { return NIL; } if (IS_PGXC_COORDINATOR && IsConnFromCoord()) { return NIL; } } /* * Now fold the CTAS statement into an INSERT INTO statement. The * utility is no more required. */ parsetree->utilityStmt = NULL; char* insert_into_sqlstr = GetInsertIntoStmt(stmt); raw_parsetree_list = pg_parse_query(insert_into_sqlstr); Assert(IsA(linitial(raw_parsetree_list), InsertStmt)); linitial_node(InsertStmt, raw_parsetree_list)->isRewritten = true; if (stmt->parserSetup != NULL) return pg_analyze_and_rewrite_params( (Node*)linitial(raw_parsetree_list), insert_into_sqlstr, (ParserSetupHook)stmt->parserSetup, stmt->parserSetupArg); else { if (strchr(insert_into_sqlstr, '$') == NULL) { return pg_analyze_and_rewrite((Node*)linitial(raw_parsetree_list), insert_into_sqlstr, NULL, 0); } else { /* For plpy CTAS with $1, $2... */ return pg_analyze_and_rewrite((Node*)linitial(raw_parsetree_list), insert_into_sqlstr, parsetree->fixed_paramTypes, parsetree->fixed_numParams); } } } /* * User_defined variables is a string in prepareStmt. * Get selectStmt/insertStmt/updateStmt/deleteStmt/mergeStmt from user_defined variables by pg_parse_query. * Then, execute SQL: PREPARE stmt AS selectStmt/insertStmt/updateStmt/deleteStmt/mergeStmt. */ List* QueryRewritePrepareStmt(Query* parsetree) { char *sqlstr = NULL; List* raw_parsetree_list = NIL; List* querytree_list = NULL; PrepareStmt *stmt = (PrepareStmt *)parsetree->utilityStmt; UserVar *uservar = (UserVar *)stmt->query; Const* value = (Const *)uservar->value; if (value->consttype != TEXTOID) { ereport(ERROR, (errcode(ERRCODE_UNRECOGNIZED_NODE_TYPE), errmsg("userdefined variable in prepare statement must be text type."))); } sqlstr = TextDatumGetCString(value->constvalue); raw_parsetree_list = pg_parse_query(sqlstr); if (raw_parsetree_list->length != 1) { ereport(ERROR, (errcode(ERRCODE_UNRECOGNIZED_NODE_TYPE), errmsg("prepare user_defined variable can contain only one SQL statement."))); } switch (nodeTag(linitial(raw_parsetree_list))) { case T_SelectStmt: case T_InsertStmt: case T_UpdateStmt: case T_DeleteStmt: case T_MergeStmt: stmt->query = (Node *)copyObject((Node *)linitial(raw_parsetree_list)); break; default: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("the statement in prepare is not supported."))); break; } querytree_list = pg_analyze_and_rewrite((Node*)stmt, sqlstr, NULL, 0); return querytree_list; } /* * Get value from a subquery or non-constant expression by constructing SQL. * input: node: a subquery expression or non-constant expression. * return: Const expression. */ Node* QueryRewriteNonConstant(Node *node) { Query* cparsetree = NULL; Const* con = NULL; List *p_target = NIL; Node *res = NULL; SelectStmt* select_stmt = makeNode(SelectStmt); /* get targetList. */ TargetEntry* target = makeTargetEntry((Expr*)node, (AttrNumber)1, NULL, false); p_target = list_make1(target); select_stmt->targetList = list_copy(p_target); /* construct Query node for subquery. */ cparsetree = (Query *)makeNode(Query); cparsetree->commandType = CMD_SELECT; cparsetree->utilityStmt = (Node *)select_stmt; cparsetree->hasSubLinks = true; cparsetree->canSetTag = true; cparsetree->jointree = makeFromExpr(NULL, NULL); cparsetree->targetList = list_copy(p_target); StringInfo select_sql = makeStringInfo(); /* deparse the SQL statement from the subquery. */ deparse_query(cparsetree, select_sql, NIL, false, false); StmtResult *result = execute_stmt(select_sql->data, true); DestroyStringInfo(select_sql); bool isnull = result->isnulls[0]; if (isnull) { /* return a null const */ con = makeConst(UNKNOWNOID, -1, InvalidOid, -2, (Datum)0, true, false); (*result->pub.rDestroy)((DestReceiver *)result); return (Node *)con; } char* value = (char *)linitial((List *)linitial(result->tuples)); uint len = strlen(value); char* str_value = (char *)palloc(len + 1); errno_t rc = strncpy_s(str_value, len + 1, value, len + 1); securec_check(rc, "\0", "\0"); str_value[len] = '\0'; Datum str_datum = CStringGetDatum(str_value); Oid atttypid = result->atttypids[0]; /* convert value to const expression. */ if (atttypid == BOOLOID) { if (strcmp(str_value, "t") == 0) { con = makeConst(BOOLOID, -1, InvalidOid, sizeof(bool), BoolGetDatum(true), false, true); } else { con = makeConst(BOOLOID, -1, InvalidOid, sizeof(bool), BoolGetDatum(false), false, true); } res = (Node *)con; } else { con = makeConst(UNKNOWNOID, -1, InvalidOid, -2, str_datum, false, false); res = type_transfer((Node *)con, atttypid, true); } (*result->pub.rDestroy)((DestReceiver *)result); return res; } #endif