1 files changed, 37 insertions, 0 deletions
diff --git a/src/test/regress/sql/create_index.sql b/src/test/regress/sql/create_index.sql
index 8b353be16e..9003950a1f 100644
--- a/src/test/regress/sql/create_index.sql
+++ b/src/test/regress/sql/create_index.sql
@@ -388,6 +388,43 @@ RESET maintenance_work_mem;
 
 
 --
+-- Test unique null behavior
+--
+CREATE TABLE unique_tbl (i int, t text);
+
+CREATE UNIQUE INDEX unique_idx1 ON unique_tbl (i) NULLS DISTINCT;
+CREATE UNIQUE INDEX unique_idx2 ON unique_tbl (i) NULLS NOT DISTINCT;
+
+INSERT INTO unique_tbl VALUES (1, 'one');
+INSERT INTO unique_tbl VALUES (2, 'two');
+INSERT INTO unique_tbl VALUES (3, 'three');
+INSERT INTO unique_tbl VALUES (4, 'four');
+INSERT INTO unique_tbl VALUES (5, 'one');
+INSERT INTO unique_tbl (t) VALUES ('six');
+INSERT INTO unique_tbl (t) VALUES ('seven');  -- error from unique_idx2
+
+DROP INDEX unique_idx1, unique_idx2;
+
+INSERT INTO unique_tbl (t) VALUES ('seven');
+
+-- build indexes on filled table
+CREATE UNIQUE INDEX unique_idx3 ON unique_tbl (i) NULLS DISTINCT;  -- ok
+CREATE UNIQUE INDEX unique_idx4 ON unique_tbl (i) NULLS NOT DISTINCT;  -- error
+
+DELETE FROM unique_tbl WHERE t = 'seven';
+
+CREATE UNIQUE INDEX unique_idx4 ON unique_tbl (i) NULLS NOT DISTINCT;  -- ok now
+
+\d unique_tbl
+\d unique_idx3
+\d unique_idx4
+SELECT pg_get_indexdef('unique_idx3'::regclass);
+SELECT pg_get_indexdef('unique_idx4'::regclass);
+
+DROP TABLE unique_tbl;
+
+
+--
 -- Test functional index
 --
 CREATE TABLE func_index_heap (f1 text, f2 text);