postgres
diff --git a/‎src/backend/access/heap/rewriteheap.c
Copy file name to clipboardExpand all lines: src/backend/access/heap/rewriteheap.c
+5-1Lines changed: 5 additions & 1 deletion b/‎src/backend/access/heap/rewriteheap.c
Copy file name to clipboardExpand all lines: src/backend/access/heap/rewriteheap.c
+5-1Lines changed: 5 additions & 1 deletion
diff --git a/‎src/test/regress/expected/cluster.out
Copy file name to clipboardExpand all lines: src/test/regress/expected/cluster.out
+5Lines changed: 5 additions & 0 deletions b/‎src/test/regress/expected/cluster.out
Copy file name to clipboardExpand all lines: src/test/regress/expected/cluster.out
+5Lines changed: 5 additions & 0 deletions
diff --git a/‎src/test/regress/sql/cluster.sql
Copy file name to clipboardExpand all lines: src/test/regress/sql/cluster.sql
+6Lines changed: 6 additions & 0 deletions b/‎src/test/regress/sql/cluster.sql
Copy file name to clipboardExpand all lines: src/test/regress/sql/cluster.sql
+6Lines changed: 6 additions & 0 deletions
@@ -324,10 +324,10 @@ end_heap_rewrite(RewriteState state)
 						state->rs_blockno,
 						state->rs_buffer,
 						true);
-		RelationOpenSmgr(state->rs_new_rel);
 
 		PageSetChecksumInplace(state->rs_buffer, state->rs_blockno);
 
+		RelationOpenSmgr(state->rs_new_rel);
 		smgrextend(state->rs_new_rel->rd_smgr, MAIN_FORKNUM, state->rs_blockno,
 				   (char *) state->rs_buffer, true);
 	}
@@ -340,7 +340,11 @@ end_heap_rewrite(RewriteState state)
 	 * wrote before the checkpoint.
 	 */
 	if (RelationNeedsWAL(state->rs_new_rel))
+	{
+		/* for an empty table, this could be first smgr access */
+		RelationOpenSmgr(state->rs_new_rel);
 		smgrimmedsync(state->rs_new_rel->rd_smgr, MAIN_FORKNUM);
+	}
 
 	logical_end_heap_rewrite(state);
 
 
@@ -439,6 +439,11 @@ select * from clstr_temp;
 
 drop table clstr_temp;
 RESET SESSION AUTHORIZATION;
+-- check clustering an empty table
+DROP TABLE clustertest;
+CREATE TABLE clustertest (f1 int PRIMARY KEY);
+CLUSTER clustertest USING clustertest_pkey;
+CLUSTER clustertest;
 -- Check that partitioned tables cannot be clustered
 CREATE TABLE clstrpart (a int) PARTITION BY RANGE (a);
 CREATE INDEX clstrpart_idx ON clstrpart (a);
 
@@ -196,6 +196,12 @@ drop table clstr_temp;
 
 RESET SESSION AUTHORIZATION;
 
+-- check clustering an empty table
+DROP TABLE clustertest;
+CREATE TABLE clustertest (f1 int PRIMARY KEY);
+CLUSTER clustertest USING clustertest_pkey;
+CLUSTER clustertest;
+
 -- Check that partitioned tables cannot be clustered
 CREATE TABLE clstrpart (a int) PARTITION BY RANGE (a);
 CREATE INDEX clstrpart_idx ON clstrpart (a);