Address stats import review comments.

Reported-by: jian he <jian.universality@gmail.com>
Discussion: https://postgr.es/m/CACJufxHG9MBQozbJQ4JRBcRbUO+t+sx4qLZX092rS_9b4SR_EA@mail.gmail.com

src/backend/statistics/relation_stats.c

@@ -127,13 +127,7 @@ relation_statistics_update(FunctionCallInfo fcinfo)
 
 	ctup = SearchSysCache1(RELOID, ObjectIdGetDatum(reloid));
 	if (!HeapTupleIsValid(ctup))
-	{
+		elog(ERROR, "pg_class entry for relid %u not found", reloid);
-		ereport(WARNING,
-				(errcode(ERRCODE_OBJECT_IN_USE),
-				 errmsg("pg_class entry for relid %u not found", reloid)));
-		table_close(crel, RowExclusiveLock);
-		return false;
-	}
 
 	pgcform = (Form_pg_class) GETSTRUCT(ctup);
 

src/backend/statistics/stat_utils.c

@@ -136,12 +136,14 @@ stats_lock_check_privileges(Oid reloid)
 
 	/*
 	 * For indexes, we follow the locking behavior in do_analyze_rel() and
-	 * check_inplace_rel_lock(), which is to lock the table first in
+	 * check_lock_if_inplace_updateable_rel(), which is to lock the table
-	 * ShareUpdateExclusive mode and then the index in AccessShare mode.
+	 * first in ShareUpdateExclusive mode and then the index in AccessShare
+	 * mode.
 	 *
 	 * Partitioned indexes are treated differently than normal indexes in
-	 * check_inplace_rel_lock(), so we take a ShareUpdateExclusive lock on
+	 * check_lock_if_inplace_updateable_rel(), so we take a
-	 * both the partitioned table and the partitioned index.
+	 * ShareUpdateExclusive lock on both the partitioned table and the
+	 * partitioned index.
 	 */
 	switch (get_rel_relkind(reloid))
 	{