diff options
Diffstat (limited to 'src/backend/utils')
| -rw-r--r-- | src/backend/utils/cache/relcache.c | 78 |
1 files changed, 37 insertions, 41 deletions
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c index 686fcc8416b..983055ef783 100644 --- a/src/backend/utils/cache/relcache.c +++ b/src/backend/utils/cache/relcache.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.161 2002/04/18 20:01:09 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.162 2002/04/19 16:36:08 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -635,10 +635,10 @@ RelationBuildRuleLock(Relation relation) { MemoryContext rulescxt; MemoryContext oldcxt; - HeapTuple pg_rewrite_tuple; - Relation pg_rewrite_desc; - TupleDesc pg_rewrite_tupdesc; - SysScanDesc pg_rewrite_scan; + HeapTuple rewrite_tuple; + Relation rewrite_desc; + TupleDesc rewrite_tupdesc; + SysScanDesc rewrite_scan; ScanKeyData key; RuleLock *rulelock; int numlocks; @@ -657,7 +657,7 @@ RelationBuildRuleLock(Relation relation) relation->rd_rulescxt = rulescxt; /* - * form an array to hold the rewrite rules (the array is extended if + * allocate an array to hold the rewrite rules (the array is extended if * necessary) */ maxlocks = 4; @@ -675,18 +675,22 @@ RelationBuildRuleLock(Relation relation) /* * open pg_rewrite and begin a scan - */ - pg_rewrite_desc = heap_openr(RewriteRelationName, AccessShareLock); - pg_rewrite_tupdesc = RelationGetDescr(pg_rewrite_desc); - pg_rewrite_scan = systable_beginscan(pg_rewrite_desc, - RewriteRelRulenameIndex, - criticalRelcachesBuilt, - SnapshotNow, - 1, &key); - - while (HeapTupleIsValid(pg_rewrite_tuple = systable_getnext(pg_rewrite_scan))) + * + * Note: since we scan the rules using RewriteRelRulenameIndex, + * we will be reading the rules in name order, except possibly + * during emergency-recovery operations (ie, IsIgnoringSystemIndexes). + * This in turn ensures that rules will be fired in name order. + */ + rewrite_desc = heap_openr(RewriteRelationName, AccessShareLock); + rewrite_tupdesc = RelationGetDescr(rewrite_desc); + rewrite_scan = systable_beginscan(rewrite_desc, + RewriteRelRulenameIndex, + true, SnapshotNow, + 1, &key); + + while (HeapTupleIsValid(rewrite_tuple = systable_getnext(rewrite_scan))) { - Form_pg_rewrite rewrite_form = (Form_pg_rewrite) GETSTRUCT(pg_rewrite_tuple); + Form_pg_rewrite rewrite_form = (Form_pg_rewrite) GETSTRUCT(rewrite_tuple); bool isnull; Datum ruleaction; Datum rule_evqual; @@ -697,7 +701,7 @@ RelationBuildRuleLock(Relation relation) rule = (RewriteRule *) MemoryContextAlloc(rulescxt, sizeof(RewriteRule)); - rule->ruleId = pg_rewrite_tuple->t_data->t_oid; + rule->ruleId = rewrite_tuple->t_data->t_oid; rule->event = rewrite_form->ev_type - '0'; rule->attrno = rewrite_form->ev_attr; @@ -705,9 +709,9 @@ RelationBuildRuleLock(Relation relation) /* Must use heap_getattr to fetch ev_qual and ev_action */ - ruleaction = heap_getattr(pg_rewrite_tuple, + ruleaction = heap_getattr(rewrite_tuple, Anum_pg_rewrite_ev_action, - pg_rewrite_tupdesc, + rewrite_tupdesc, &isnull); Assert(!isnull); ruleaction_str = DatumGetCString(DirectFunctionCall1(textout, @@ -717,13 +721,13 @@ RelationBuildRuleLock(Relation relation) MemoryContextSwitchTo(oldcxt); pfree(ruleaction_str); - rule_evqual = heap_getattr(pg_rewrite_tuple, + rule_evqual = heap_getattr(rewrite_tuple, Anum_pg_rewrite_ev_qual, - pg_rewrite_tupdesc, + rewrite_tupdesc, &isnull); Assert(!isnull); rule_evqual_str = DatumGetCString(DirectFunctionCall1(textout, - rule_evqual)); + rule_evqual)); oldcxt = MemoryContextSwitchTo(rulescxt); rule->qual = (Node *) stringToNode(rule_evqual_str); MemoryContextSwitchTo(oldcxt); @@ -741,8 +745,8 @@ RelationBuildRuleLock(Relation relation) /* * end the scan and close the attribute relation */ - systable_endscan(pg_rewrite_scan); - heap_close(pg_rewrite_desc, AccessShareLock); + systable_endscan(rewrite_scan); + heap_close(rewrite_desc, AccessShareLock); /* * form a RuleLock and insert into relation @@ -764,9 +768,13 @@ RelationBuildRuleLock(Relation relation) static bool equalRuleLocks(RuleLock *rlock1, RuleLock *rlock2) { - int i, - j; + int i; + /* + * As of 7.3 we assume the rule ordering is repeatable, + * because RelationBuildRuleLock should read 'em in a + * consistent order. So just compare corresponding slots. + */ if (rlock1 != NULL) { if (rlock2 == NULL) @@ -776,21 +784,9 @@ equalRuleLocks(RuleLock *rlock1, RuleLock *rlock2) for (i = 0; i < rlock1->numLocks; i++) { RewriteRule *rule1 = rlock1->rules[i]; - RewriteRule *rule2 = NULL; + RewriteRule *rule2 = rlock2->rules[i]; - /* - * We can't assume that the rules are always read from - * pg_rewrite in the same order; so use the rule OIDs to - * identify the rules to compare. (We assume here that the - * same OID won't appear twice in either ruleset.) - */ - for (j = 0; j < rlock2->numLocks; j++) - { - rule2 = rlock2->rules[j]; - if (rule1->ruleId == rule2->ruleId) - break; - } - if (j >= rlock2->numLocks) + if (rule1->ruleId != rule2->ruleId) return false; if (rule1->event != rule2->event) return false; |