2 files changed, 73 insertions, 0 deletions
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index 075637ce56d..46402b4a6d3 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -3109,3 +3109,51 @@ ALTER TABLE logged1 SET UNLOGGED; -- silently do nothing
 DROP TABLE logged3;
 DROP TABLE logged2;
 DROP TABLE logged1;
+-- Test that ALTER TABLE rewrite preserves a clustered index
+-- for normal indexes and indexes on constraints.
+create table alttype_cluster (a int);
+alter table alttype_cluster add primary key (a);
+create index alttype_cluster_ind on alttype_cluster (a);
+alter table alttype_cluster cluster on alttype_cluster_ind;
+-- Normal index remains clustered.
+select indexrelid::regclass, indisclustered from pg_index
+  where indrelid = 'alttype_cluster'::regclass
+  order by indexrelid::regclass::text;
+      indexrelid      | indisclustered 
+----------------------+----------------
+ alttype_cluster_ind  | t
+ alttype_cluster_pkey | f
+(2 rows)
+
+alter table alttype_cluster alter a type bigint;
+select indexrelid::regclass, indisclustered from pg_index
+  where indrelid = 'alttype_cluster'::regclass
+  order by indexrelid::regclass::text;
+      indexrelid      | indisclustered 
+----------------------+----------------
+ alttype_cluster_ind  | t
+ alttype_cluster_pkey | f
+(2 rows)
+
+-- Constraint index remains clustered.
+alter table alttype_cluster cluster on alttype_cluster_pkey;
+select indexrelid::regclass, indisclustered from pg_index
+  where indrelid = 'alttype_cluster'::regclass
+  order by indexrelid::regclass::text;
+      indexrelid      | indisclustered 
+----------------------+----------------
+ alttype_cluster_ind  | f
+ alttype_cluster_pkey | t
+(2 rows)
+
+alter table alttype_cluster alter a type int;
+select indexrelid::regclass, indisclustered from pg_index
+  where indrelid = 'alttype_cluster'::regclass
+  order by indexrelid::regclass::text;
+      indexrelid      | indisclustered 
+----------------------+----------------
+ alttype_cluster_ind  | f
+ alttype_cluster_pkey | t
+(2 rows)
+
+drop table alttype_cluster;
diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql
index 5f06a768545..421d4c7d312 100644
--- a/src/test/regress/sql/alter_table.sql
+++ b/src/test/regress/sql/alter_table.sql
@@ -1932,3 +1932,28 @@ ALTER TABLE logged1 SET UNLOGGED; -- silently do nothing
 DROP TABLE logged3;
 DROP TABLE logged2;
 DROP TABLE logged1;
+
+-- Test that ALTER TABLE rewrite preserves a clustered index
+-- for normal indexes and indexes on constraints.
+create table alttype_cluster (a int);
+alter table alttype_cluster add primary key (a);
+create index alttype_cluster_ind on alttype_cluster (a);
+alter table alttype_cluster cluster on alttype_cluster_ind;
+-- Normal index remains clustered.
+select indexrelid::regclass, indisclustered from pg_index
+  where indrelid = 'alttype_cluster'::regclass
+  order by indexrelid::regclass::text;
+alter table alttype_cluster alter a type bigint;
+select indexrelid::regclass, indisclustered from pg_index
+  where indrelid = 'alttype_cluster'::regclass
+  order by indexrelid::regclass::text;
+-- Constraint index remains clustered.
+alter table alttype_cluster cluster on alttype_cluster_pkey;
+select indexrelid::regclass, indisclustered from pg_index
+  where indrelid = 'alttype_cluster'::regclass
+  order by indexrelid::regclass::text;
+alter table alttype_cluster alter a type int;
+select indexrelid::regclass, indisclustered from pg_index
+  where indrelid = 'alttype_cluster'::regclass
+  order by indexrelid::regclass::text;
+drop table alttype_cluster;