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/*-------------------------------------------------------------------------
*
* rewriteRemove.c
* routines for removing rewrite rules
*
* Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/rewrite/rewriteRemove.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/genam.h"
#include "access/htup_details.h"
#include "access/sysattr.h"
#include "access/table.h"
#include "catalog/catalog.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
#include "catalog/pg_rewrite.h"
#include "miscadmin.h"
#include "rewrite/rewriteRemove.h"
#include "utils/acl.h"
#include "utils/fmgroids.h"
#include "utils/inval.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/syscache.h"
/*
* Guts of rule deletion.
*/
void
RemoveRewriteRuleById(Oid ruleOid)
{
Relation RewriteRelation;
ScanKeyData skey[1];
SysScanDesc rcscan;
Relation event_relation;
HeapTuple tuple;
Oid eventRelationOid;
/*
* Open the pg_rewrite relation.
*/
RewriteRelation = table_open(RewriteRelationId, RowExclusiveLock);
/*
* Find the tuple for the target rule.
*/
ScanKeyInit(&skey[0],
Anum_pg_rewrite_oid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(ruleOid));
rcscan = systable_beginscan(RewriteRelation, RewriteOidIndexId, true,
NULL, 1, skey);
tuple = systable_getnext(rcscan);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "could not find tuple for rule %u", ruleOid);
/*
* We had better grab AccessExclusiveLock to ensure that no queries are
* going on that might depend on this rule. (Note: a weaker lock would
* suffice if it's not an ON SELECT rule.)
*/
eventRelationOid = ((Form_pg_rewrite) GETSTRUCT(tuple))->ev_class;
event_relation = table_open(eventRelationOid, AccessExclusiveLock);
if (!allowSystemTableMods && IsSystemRelation(event_relation))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied: \"%s\" is a system catalog",
RelationGetRelationName(event_relation))));
/*
* Now delete the pg_rewrite tuple for the rule
*/
CatalogTupleDelete(RewriteRelation, &tuple->t_self);
systable_endscan(rcscan);
table_close(RewriteRelation, RowExclusiveLock);
/*
* Issue shared-inval notice to force all backends (including me!) to
* update relcache entries with the new rule set.
*/
CacheInvalidateRelcache(event_relation);
/* Close rel, but keep lock till commit... */
table_close(event_relation, NoLock);
}
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