diff --git a/src/backend/cdb/cdbrelsize.c b/src/backend/cdb/cdbrelsize.c
index a02bc1be4c738dcf68dbe811ec79bd5f47acf03b..033e09379b22cde4563aacb1cb2a54cbbe28986c 100644
--- a/src/backend/cdb/cdbrelsize.c
+++ b/src/backend/cdb/cdbrelsize.c
@@ -8,8 +8,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
-
 #include "utils/lsyscache.h"
 #include "utils/relcache.h"
 #include "utils/syscache.h"
@@ -37,26 +35,16 @@ cdbRelMaxSegSize(Relation rel)
 	CdbPgResults cdb_pgresults = {NULL, 0};
 	StringInfoData buffer;
 
-	char *schemaName;
-	char *relName;
-
 	/*
 	 * Let's ask the QEs for the size of the relation
 	 */
 	initStringInfo(&buffer);
 
-	schemaName = get_namespace_name(RelationGetNamespace(rel));
-	if (schemaName == NULL)
-		elog(ERROR, "cache lookup failed for namespace %d",
-			 RelationGetNamespace(rel));
-	relName = RelationGetRelationName(rel);
-
 	/*
-	 * Safer to pass names than oids, just in case they get out of sync between QD and QE,
-	 * which might happen with a toast table or index, I think (but maybe not)
+	 * Relation Oids are assumed to be in sync in all nodes.
 	 */
-	appendStringInfo(&buffer, "select pg_relation_size('%s.%s')",
-					 quote_identifier(schemaName), quote_identifier(relName));
+	appendStringInfo(&buffer, "select pg_relation_size(%u)",
+					 RelationGetRelid(rel));
 
 	CdbDispatchCommand(buffer.data, DF_WITH_SNAPSHOT, &cdb_pgresults);
 
diff --git a/src/test/regress/expected/alter_table_gp.out b/src/test/regress/expected/alter_table_gp.out
index 5476f189661f6b3418ddd0ae3d7ed87edaa81be9..ebaf15a3b31f6fad0ee93ea5d1f3abfb76c6b326 100644
--- a/src/test/regress/expected/alter_table_gp.out
+++ b/src/test/regress/expected/alter_table_gp.out
@@ -125,3 +125,7 @@ SELECT * FROM altable ORDER BY 1;
  0 | 1
 (1 row)
 
+-- Verify that changing the datatype of a funnily-named column works.
+-- (There used to be a quoting bug in the internal query this issues.)
+create table "foo'bar" (id int4, t text);
+alter table "foo'bar" alter column t type integer using length(t);
diff --git a/src/test/regress/expected/alter_table_gp_optimizer.out b/src/test/regress/expected/alter_table_gp_optimizer.out
index 1aa7cf276e7b40eb01518f832e17e116f739f0cb..a9165bb11aa69cb4c3174e20658853d0f498a4e2 100644
--- a/src/test/regress/expected/alter_table_gp_optimizer.out
+++ b/src/test/regress/expected/alter_table_gp_optimizer.out
@@ -127,3 +127,7 @@ SELECT * FROM altable ORDER BY 1;
  0 | 1
 (1 row)
 
+-- Verify that changing the datatype of a funnily-named column works.
+-- (There used to be a quoting bug in the internal query this issues.)
+create table "foo'bar" (id int4, t text);
+alter table "foo'bar" alter column t type integer using length(t);
diff --git a/src/test/regress/sql/alter_table_gp.sql b/src/test/regress/sql/alter_table_gp.sql
index 8204f57d1b5654e18664d8b76dc6768683e5c173..3a23c937bfc5dc2ea0e6d705bb37a43873d92456 100644
--- a/src/test/regress/sql/alter_table_gp.sql
+++ b/src/test/regress/sql/alter_table_gp.sql
@@ -82,3 +82,9 @@ UPDATE altable SET c = -10;
 SELECT * FROM altable ORDER BY 1;
 UPDATE altable SET c = 1;
 SELECT * FROM altable ORDER BY 1;
+
+
+-- Verify that changing the datatype of a funnily-named column works.
+-- (There used to be a quoting bug in the internal query this issues.)
+create table "foo'bar" (id int4, t text);
+alter table "foo'bar" alter column t type integer using length(t);