/*
* Guts of rule deletion.
*/
void
RemoveRewriteRuleById(Oid ruleOid)
{
cqContext *pcqCtx;
Relation event_relation;
HeapTuple tuple;
Oid eventRelationOid;
bool hasMoreRules;
/*
* Find the tuple for the target rule.
*/
pcqCtx = caql_beginscan(
NULL,
cql("SELECT * FROM pg_rewrite "
" WHERE oid = :1 "
" FOR UPDATE ",
ObjectIdGetDatum(ruleOid)));
tuple = caql_getnext(pcqCtx);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "could not find tuple for rule %u", ruleOid);
/*
* 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.
*/
eventRelationOid = ((Form_pg_rewrite) GETSTRUCT(tuple))->ev_class;
event_relation = heap_open(eventRelationOid, AccessExclusiveLock);
hasMoreRules = event_relation->rd_rules != NULL &&
event_relation->rd_rules->numLocks > 1;
/*
* Now delete the pg_rewrite tuple for the rule
*/
caql_delete_current(pcqCtx);
caql_endscan(pcqCtx);
/*
* 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!
*/
SetRelationRuleStatus(eventRelationOid, hasMoreRules, false);
/* Close rel, but keep lock till commit... */
heap_close(event_relation, NoLock);
}
/*
* Guts of rule deletion.
*/
void
RemoveRewriteRuleById(Oid ruleOid)
{
Relation RewriteRelation;
ScanKeyData skey[1];
SysScanDesc rcscan;
Relation event_relation;
HeapTuple tuple;
Oid eventRelationOid;
bool hasMoreRules;
/*
* Open the pg_rewrite relation.
*/
RewriteRelation = heap_open(RewriteRelationId, RowExclusiveLock);
/*
* Find the tuple for the target rule.
*/
ScanKeyInit(&skey[0],
ObjectIdAttributeNumber,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(ruleOid));
rcscan = systable_beginscan(RewriteRelation, RewriteOidIndexId, true,
SnapshotNow, 1, skey);
tuple = systable_getnext(rcscan);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "could not find tuple for rule %u", ruleOid);
/*
* 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.
*/
eventRelationOid = ((Form_pg_rewrite) GETSTRUCT(tuple))->ev_class;
event_relation = heap_open(eventRelationOid, AccessExclusiveLock);
hasMoreRules = event_relation->rd_rules != NULL &&
event_relation->rd_rules->numLocks > 1;
/*
* Now delete the pg_rewrite tuple for the rule
*/
simple_heap_delete(RewriteRelation, &tuple->t_self);
systable_endscan(rcscan);
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!
*/
SetRelationRuleStatus(eventRelationOid, hasMoreRules, false);
/* Close rel, but keep lock till commit... */
heap_close(event_relation, NoLock);
}
