Implement IS NOT DISTINCT FROM, update the regression tests and docs.

Patch from Pavel Stehule, minor fixups by myself.

2 files changed, 31 insertions, 0 deletions

diff --git a/src/test/regress/expected/select_distinct.out b/src/test/regress/expected/select_distinct.out
index 019638ed176..abe34ae7ae5 100644
--- a/src/test/regress/expected/select_distinct.out
+++ b/src/test/regress/expected/select_distinct.out
@@ -195,3 +195,28 @@ SELECT null IS DISTINCT FROM null as "no";
  f
 (1 row)
 
+-- ANSI SQL 2003 form
+SELECT 1 IS NOT DISTINCT FROM 2 as "no";
+ no 
+----
+ f
+(1 row)
+
+SELECT 2 IS NOT DISTINCT FROM 2 as "yes";
+ yes 
+-----
+ t
+(1 row)
+
+SELECT 2 IS NOT DISTINCT FROM null as "no";
+ no 
+----
+ f
+(1 row)
+
+SELECT null IS NOT DISTINCT FROM null as "yes";
+ yes 
+-----
+ t
+(1 row)
+
diff --git a/src/test/regress/sql/select_distinct.sql b/src/test/regress/sql/select_distinct.sql
index 94032c312ee..c4a63aaf16f 100644
--- a/src/test/regress/sql/select_distinct.sql
+++ b/src/test/regress/sql/select_distinct.sql
@@ -56,3 +56,9 @@ SELECT 1 IS DISTINCT FROM 2 as "yes";
 SELECT 2 IS DISTINCT FROM 2 as "no";
 SELECT 2 IS DISTINCT FROM null as "yes";
 SELECT null IS DISTINCT FROM null as "no";
+
+-- ANSI SQL 2003 form
+SELECT 1 IS NOT DISTINCT FROM 2 as "no";
+SELECT 2 IS NOT DISTINCT FROM 2 as "yes";
+SELECT 2 IS NOT DISTINCT FROM null as "no";
+SELECT null IS NOT DISTINCT FROM null as "yes";