diff options
Diffstat (limited to 'src/backend/rewrite/rewriteRemove.c')
| -rw-r--r-- | src/backend/rewrite/rewriteRemove.c | 73 |
1 files changed, 34 insertions, 39 deletions
diff --git a/src/backend/rewrite/rewriteRemove.c b/src/backend/rewrite/rewriteRemove.c index 13a07adbd8c..d50e1049097 100644 --- a/src/backend/rewrite/rewriteRemove.c +++ b/src/backend/rewrite/rewriteRemove.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteRemove.c,v 1.37 2000/05/28 17:56:02 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteRemove.c,v 1.38 2000/06/30 07:04:23 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -52,30 +52,20 @@ RewriteGetRuleEventRel(char *rulename) return NameStr(((Form_pg_class) GETSTRUCT(htup))->relname); } -/* ---------------------------------------------------------------- - * +/* * RemoveRewriteRule * * Delete a rule given its rulename. - * - * There are three steps. - * 1) Find the corresponding tuple in 'pg_rewrite' relation. - * Find the rule Id (i.e. the Oid of the tuple) and finally delete - * the tuple. - * 3) Delete the locks from the 'pg_class' relation. - * - * - * ---------------------------------------------------------------- */ void RemoveRewriteRule(char *ruleName) { - Relation RewriteRelation = NULL; - HeapTuple tuple = NULL; - Oid ruleId = (Oid) 0; - Oid eventRelationOid = (Oid) NULL; - Datum eventRelationOidDatum = (Datum) NULL; - bool isNull = false; + Relation RewriteRelation; + Relation event_relation; + HeapTuple tuple; + Oid ruleId; + Oid eventRelationOid; + bool hasMoreRules; /* * Open the pg_rewrite relation. @@ -83,7 +73,7 @@ RemoveRewriteRule(char *ruleName) RewriteRelation = heap_openr(RewriteRelationName, RowExclusiveLock); /* - * Scan the RuleRelation ('pg_rewrite') until we find a tuple + * Find the tuple for the target rule. */ tuple = SearchSysCacheTupleCopy(RULENAME, PointerGetDatum(ruleName), @@ -99,44 +89,49 @@ RemoveRewriteRule(char *ruleName) } /* - * Store the OID of the rule (i.e. the tuple's OID) and the event + * Save the OID of the rule (i.e. the tuple's OID) and the event * relation's OID */ ruleId = tuple->t_data->t_oid; - eventRelationOidDatum = heap_getattr(tuple, - Anum_pg_rewrite_ev_class, - RelationGetDescr(RewriteRelation), - &isNull); - if (isNull) - { - /* XXX strange!!! */ - heap_freetuple(tuple); - elog(ERROR, "RemoveRewriteRule: internal error; null event target relation!"); - } - eventRelationOid = DatumGetObjectId(eventRelationOidDatum); + eventRelationOid = ((Form_pg_rewrite) GETSTRUCT(tuple))->ev_class; /* - * Now delete the relation level locks from the updated relation. - * (Make sure we do this before we remove the rule from pg_rewrite. - * Otherwise, heap_openr on eventRelationOid which reads pg_rwrite for - * the rules will fail.) + * We had better grab AccessExclusiveLock so that we know no other + * rule additions/deletions are going on for this relation. Else + * we cannot set relhasrules correctly. Besides, we don't want to + * be changing the ruleset while queries are executing on the rel. */ - prs2_deleteFromRelation(eventRelationOid, ruleId); + event_relation = heap_open(eventRelationOid, AccessExclusiveLock); + + hasMoreRules = event_relation->rd_rules != NULL && + event_relation->rd_rules->numLocks > 1; /* * Delete any comments associated with this rule - * */ - DeleteComments(ruleId); /* - * Now delete the tuple... + * Now delete the pg_rewrite tuple for the rule */ heap_delete(RewriteRelation, &tuple->t_self, NULL); heap_freetuple(tuple); + heap_close(RewriteRelation, RowExclusiveLock); + + /* + * Set pg_class 'relhasrules' field correctly for event relation. + * + * Important side effect: an SI notice is broadcast to force all + * backends (including me!) to update relcache entries with the + * new rule set. Therefore, must do this even if relhasrules is + * still true! + */ + setRelhasrulesInRelation(eventRelationOid, hasMoreRules); + + /* Close rel, but keep lock till commit... */ + heap_close(event_relation, NoLock); } /* |