Adding upstream version 14.5.upstream/14.5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 100 insertions, 0 deletions

diff --git a/src/backend/rewrite/rewriteRemove.c b/src/backend/rewrite/rewriteRemove.c
new file mode 100644
index 0000000..a48b15e
--- /dev/null
+++ b/src/backend/rewrite/rewriteRemove.c
@@ -0,0 +1,100 @@
+/*-------------------------------------------------------------------------
+ *
+ * rewriteRemove.c
+ *	  routines for removing rewrite rules
+ *
+ * Portions Copyright (c) 1996-2021, 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);
+}