Create functions pg_set_relation_stats, pg_clear_relation_stats.

These functions are used to tweak statistics on any relation, provided
that the user has MAINTAIN privilege on the relation, or is the database
owner.

Bump catalog version.

Author: Corey Huinker
Discussion: https://postgr.es/m/CADkLM=eErgzn7ECDpwFcptJKOk9SxZEk5Pot4d94eVTZsvj3gw@mail.gmail.com

1 files changed, 94 insertions, 0 deletions

diff --git a/src/backend/statistics/stat_utils.c b/src/backend/statistics/stat_utils.c
new file mode 100644
index 00000000000..4babed2e5d7
--- /dev/null
+++ b/src/backend/statistics/stat_utils.c
@@ -0,0 +1,94 @@
+/*-------------------------------------------------------------------------
+ * stat_utils.c
+ *
+ *	  PostgreSQL statistics manipulation utilities.
+ *
+ * Code supporting the direct manipulation of statistics.
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *       src/backend/statistics/stat_utils.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/relation.h"
+#include "catalog/pg_database.h"
+#include "miscadmin.h"
+#include "statistics/stat_utils.h"
+#include "utils/array.h"
+#include "utils/builtins.h"
+#include "utils/acl.h"
+#include "utils/rel.h"
+
+/*
+ * Ensure that a given argument is not null.
+ */
+void
+stats_check_required_arg(FunctionCallInfo fcinfo,
+						 struct StatsArgInfo *arginfo,
+						 int argnum)
+{
+	if (PG_ARGISNULL(argnum))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("\"%s\" cannot be NULL",
+						arginfo[argnum].argname)));
+}
+
+/*
+ * Lock relation in ShareUpdateExclusive mode, check privileges, and close the
+ * relation (but retain the lock).
+ *
+ * A role has privileges to set statistics on the relation if any of the
+ * following are true:
+ *   - the role owns the current database and the relation is not shared
+ *   - the role has the MAINTAIN privilege on the relation
+ */
+void
+stats_lock_check_privileges(Oid reloid)
+{
+	Relation	rel = relation_open(reloid, ShareUpdateExclusiveLock);
+	const char	relkind = rel->rd_rel->relkind;
+
+	/* All of the types that can be used with ANALYZE, plus indexes */
+	switch (relkind)
+	{
+		case RELKIND_RELATION:
+		case RELKIND_INDEX:
+		case RELKIND_MATVIEW:
+		case RELKIND_FOREIGN_TABLE:
+		case RELKIND_PARTITIONED_TABLE:
+		case RELKIND_PARTITIONED_INDEX:
+			break;
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot modify statistics for relation \"%s\"",
+							RelationGetRelationName(rel)),
+					 errdetail_relkind_not_supported(rel->rd_rel->relkind)));
+	}
+
+	if (rel->rd_rel->relisshared)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot modify statistics for shared relation")));
+
+	if (!object_ownercheck(DatabaseRelationId, MyDatabaseId, GetUserId()))
+	{
+		AclResult	aclresult = pg_class_aclcheck(RelationGetRelid(rel),
+												  GetUserId(),
+												  ACL_MAINTAIN);
+
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult,
+						   get_relkind_objtype(rel->rd_rel->relkind),
+						   NameStr(rel->rd_rel->relname));
+	}
+
+	relation_close(rel, NoLock);
+}