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Fix AcquireRewriteLocks to be sure that it acquires the right lock strength
when FOR UPDATE is propagated down into a sub-select expanded from a view. Similar bug to parser's isLockedRel issue that I fixed yesterday; likewise seems not quite worth the effort to back-patch.
This commit is contained in:
Tom Lane
parent
46e3a16b05
commit
cbcd1701f1
@ -7,7 +7,7 @@
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/rewrite/rewriteHandler.c,v 1.190 2009/10/28 14:55:43 tgl Exp $
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* $PostgreSQL: pgsql/src/backend/rewrite/rewriteHandler.c,v 1.191 2009/10/28 17:36:50 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -55,7 +55,8 @@ static void markQueryForLocking(Query *qry, Node *jtnode,
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bool forUpdate, bool noWait, bool pushedDown);
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static List *matchLocks(CmdType event, RuleLock *rulelocks,
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int varno, Query *parsetree);
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static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
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static Query *fireRIRrules(Query *parsetree, List *activeRIRs,
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bool forUpdatePushedDown);
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/*
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@ -64,6 +65,10 @@ static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
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* These locks will ensure that the relation schemas don't change under us
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* while we are rewriting and planning the query.
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*
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* forUpdatePushedDown indicates that a pushed-down FOR UPDATE/SHARE applies
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* to the current subquery, requiring all rels to be opened with RowShareLock.
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* This should always be false at the start of the recursion.
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*
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* A secondary purpose of this routine is to fix up JOIN RTE references to
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* dropped columns (see details below). Because the RTEs are modified in
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* place, it is generally appropriate for the caller of this routine to have
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@ -91,7 +96,7 @@ static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
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* construction of a nested join was O(N^2) in the nesting depth.)
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*/
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void
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AcquireRewriteLocks(Query *parsetree)
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AcquireRewriteLocks(Query *parsetree, bool forUpdatePushedDown)
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{
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ListCell *l;
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int rt_index;
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@ -129,7 +134,8 @@ AcquireRewriteLocks(Query *parsetree)
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*/
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if (rt_index == parsetree->resultRelation)
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lockmode = RowExclusiveLock;
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else if (get_parse_rowmark(parsetree, rt_index) != NULL)
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else if (forUpdatePushedDown ||
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get_parse_rowmark(parsetree, rt_index) != NULL)
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lockmode = RowShareLock;
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else
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lockmode = AccessShareLock;
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@ -206,7 +212,9 @@ AcquireRewriteLocks(Query *parsetree)
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* The subquery RTE itself is all right, but we have to
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* recurse to process the represented subquery.
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*/
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AcquireRewriteLocks(rte->subquery);
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AcquireRewriteLocks(rte->subquery,
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(forUpdatePushedDown ||
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get_parse_rowmark(parsetree, rt_index) != NULL));
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break;
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default:
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@ -220,7 +228,7 @@ AcquireRewriteLocks(Query *parsetree)
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{
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CommonTableExpr *cte = (CommonTableExpr *) lfirst(l);
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AcquireRewriteLocks((Query *) cte->ctequery);
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AcquireRewriteLocks((Query *) cte->ctequery, false);
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}
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/*
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@ -245,7 +253,7 @@ acquireLocksOnSubLinks(Node *node, void *context)
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SubLink *sub = (SubLink *) node;
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/* Do what we came for */
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AcquireRewriteLocks((Query *) sub->subselect);
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AcquireRewriteLocks((Query *) sub->subselect, false);
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/* Fall through to process lefthand args of SubLink */
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}
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@ -298,7 +306,7 @@ rewriteRuleAction(Query *parsetree,
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/*
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* Acquire necessary locks and fix any deleted JOIN RTE entries.
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*/
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AcquireRewriteLocks(rule_action);
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AcquireRewriteLocks(rule_action, false);
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(void) acquireLocksOnSubLinks(rule_qual, NULL);
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current_varno = rt_index;
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@ -1134,7 +1142,8 @@ ApplyRetrieveRule(Query *parsetree,
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int rt_index,
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bool relation_level,
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Relation relation,
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List *activeRIRs)
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List *activeRIRs,
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bool forUpdatePushedDown)
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{
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Query *rule_action;
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RangeTblEntry *rte,
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@ -1148,18 +1157,25 @@ ApplyRetrieveRule(Query *parsetree,
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if (!relation_level)
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elog(ERROR, "cannot handle per-attribute ON SELECT rule");
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/*
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* If FOR UPDATE/SHARE of view, be sure we get right initial lock on the
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* relations it references.
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*/
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rc = get_parse_rowmark(parsetree, rt_index);
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forUpdatePushedDown |= (rc != NULL);
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/*
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* Make a modifiable copy of the view query, and acquire needed locks on
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* the relations it mentions.
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*/
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rule_action = copyObject(linitial(rule->actions));
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AcquireRewriteLocks(rule_action);
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AcquireRewriteLocks(rule_action, forUpdatePushedDown);
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/*
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* Recursively expand any view references inside the view.
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*/
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rule_action = fireRIRrules(rule_action, activeRIRs);
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rule_action = fireRIRrules(rule_action, activeRIRs, forUpdatePushedDown);
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/*
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* VIEWs are really easy --- just plug the view query in as a subselect,
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@ -1192,8 +1208,11 @@ ApplyRetrieveRule(Query *parsetree,
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* If FOR UPDATE/SHARE of view, mark all the contained tables as
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* implicit FOR UPDATE/SHARE, the same as the parser would have done
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* if the view's subquery had been written out explicitly.
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*
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* Note: we don't consider forUpdatePushedDown here; such marks will be
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* made by recursing from the upper level in markQueryForLocking.
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*/
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if ((rc = get_parse_rowmark(parsetree, rt_index)) != NULL)
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if (rc != NULL)
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markQueryForLocking(rule_action, (Node *) rule_action->jointree,
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rc->forUpdate, rc->noWait, true);
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@ -1281,7 +1300,7 @@ fireRIRonSubLink(Node *node, List *activeRIRs)
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/* Do what we came for */
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sub->subselect = (Node *) fireRIRrules((Query *) sub->subselect,
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activeRIRs);
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activeRIRs, false);
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/* Fall through to process lefthand args of SubLink */
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}
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@ -1299,7 +1318,7 @@ fireRIRonSubLink(Node *node, List *activeRIRs)
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* Apply all RIR rules on each rangetable entry in a query
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*/
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static Query *
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fireRIRrules(Query *parsetree, List *activeRIRs)
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fireRIRrules(Query *parsetree, List *activeRIRs, bool forUpdatePushedDown)
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{
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int rt_index;
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ListCell *lc;
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@ -1329,7 +1348,9 @@ fireRIRrules(Query *parsetree, List *activeRIRs)
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*/
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if (rte->rtekind == RTE_SUBQUERY)
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{
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rte->subquery = fireRIRrules(rte->subquery, activeRIRs);
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rte->subquery = fireRIRrules(rte->subquery, activeRIRs,
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(forUpdatePushedDown ||
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get_parse_rowmark(parsetree, rt_index) != NULL));
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continue;
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}
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@ -1406,7 +1427,8 @@ fireRIRrules(Query *parsetree, List *activeRIRs)
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rt_index,
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rule->attrno == -1,
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rel,
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activeRIRs);
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activeRIRs,
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forUpdatePushedDown);
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}
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activeRIRs = list_delete_first(activeRIRs);
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@ -1421,7 +1443,7 @@ fireRIRrules(Query *parsetree, List *activeRIRs)
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CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
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cte->ctequery = (Node *)
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fireRIRrules((Query *) cte->ctequery, activeRIRs);
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fireRIRrules((Query *) cte->ctequery, activeRIRs, false);
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}
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/*
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@ -1850,7 +1872,7 @@ QueryRewrite(Query *parsetree)
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{
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Query *query = (Query *) lfirst(l);
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query = fireRIRrules(query, NIL);
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query = fireRIRrules(query, NIL, false);
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/*
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* If the query target was rewritten as a view, complain.
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@ -9,7 +9,7 @@
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*
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.311 2009/10/28 14:55:44 tgl Exp $
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* $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.312 2009/10/28 17:36:50 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -2175,7 +2175,7 @@ make_ruledef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
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query = getInsertSelectQuery(query, NULL);
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/* Must acquire locks right away; see notes in get_query_def() */
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AcquireRewriteLocks(query);
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AcquireRewriteLocks(query, false);
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context.buf = buf;
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context.namespaces = list_make1(&dpns);
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@ -2320,7 +2320,7 @@ get_query_def(Query *query, StringInfo buf, List *parentnamespace,
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* consistent results. Note we assume it's OK to scribble on the passed
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* querytree!
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*/
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AcquireRewriteLocks(query);
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AcquireRewriteLocks(query, false);
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context.buf = buf;
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context.namespaces = lcons(&dpns, list_copy(parentnamespace));
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@ -7,7 +7,7 @@
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* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $PostgreSQL: pgsql/src/include/rewrite/rewriteHandler.h,v 1.31 2009/01/01 17:24:01 momjian Exp $
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* $PostgreSQL: pgsql/src/include/rewrite/rewriteHandler.h,v 1.32 2009/10/28 17:36:50 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -18,7 +18,7 @@
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#include "nodes/parsenodes.h"
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extern List *QueryRewrite(Query *parsetree);
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extern void AcquireRewriteLocks(Query *parsetree);
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extern void AcquireRewriteLocks(Query *parsetree, bool forUpdatePushedDown);
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extern Node *build_column_default(Relation rel, int attrno);
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#endif /* REWRITEHANDLER_H */
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