From f6279751e4248c2bf0a1767959e4e0aef05947d3 Mon Sep 17 00:00:00 2001
From: Hadi Moshayedi <hadi@moshayedi.net>
Date: Mon, 9 Nov 2020 23:23:50 -0800
Subject: [PATCH] Don't grab in additional locks cstore code when truncating

---
 src/backend/columnar/cstore_fdw.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/backend/columnar/cstore_fdw.c b/src/backend/columnar/cstore_fdw.c
index 97e6f5a3c..ab8fa69e8 100644
--- a/src/backend/columnar/cstore_fdw.c
+++ b/src/backend/columnar/cstore_fdw.c
@@ -718,7 +718,7 @@ FindCStoreTables(List *tableList)
 	foreach(relationCell, tableList)
 	{
 		RangeVar *rangeVar = (RangeVar *) lfirst(relationCell);
-		Oid relationId = RangeVarGetRelid(rangeVar, AccessShareLock, true);
+		Oid relationId = RangeVarGetRelid(rangeVar, NoLock, true);
 		if (IsCStoreFdwTable(relationId) && !DistributedTable(relationId))
 		{
 			cstoreTableList = lappend(cstoreTableList, rangeVar);
@@ -758,6 +758,16 @@ OpenRelationsForTruncate(List *cstoreTableList)
 		{
 			heap_close(relation, AccessExclusiveLock);
 		}
+		/*
+		 * Type of cstore tables can change since we checked last time,
+		 * since we didn't hold a lock when checking.
+		 */
+		else if (!IsCStoreFdwTable(relationId))
+		{
+			ereport(ERROR, (errmsg("relation \"%s\" not columnar anymore",
+								   RelationGetRelationName(relation)),
+							errhint("try repeating the truncate command")));
+		}
 		else
 		{
 			relationIdList = lappend_oid(relationIdList, relationId);