0001-Note-NULLS-NOT-DISTINCT-on-unique-index-tutorial.patch.txt

From 5cb84716462611b84e6b2fbdb35172ec43b52db8 Mon Sep 17 00:00:00 2001
From: David Gilman <davidgilman1@gmail.com>
Date: Wed, 12 Apr 2023 10:28:09 -0400
Subject: [PATCH] Note NULLS NOT DISTINCT on unique index tutorial

---
 doc/src/sgml/indices.sgml | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/doc/src/sgml/indices.sgml b/doc/src/sgml/indices.sgml
index 0c3fcfd62f8e..0a67e66f5065 100644
--- a/doc/src/sgml/indices.sgml
+++ b/doc/src/sgml/indices.sgml
@@ -671,9 +671,11 @@ CREATE UNIQUE INDEX <replaceable>name</replaceable> ON <replaceable>table</repla
 
   <para>
    When an index is declared unique, multiple table rows with equal
-   indexed values are not allowed.  Null values are not considered
-   equal.  A multicolumn unique index will only reject cases where all
-   indexed columns are equal in multiple rows.
+   indexed values are not allowed.  By default, null values in a unique column 
+   are not considered equal, allowing multiple nulls in the column.
+   Use <literal>NULLS NOT DISTINCT</literal> to treat column nulls as equal, 
+   allowing only a single null value in an indexed column. A multicolumn unique index 
+   will only reject cases where all indexed columns are equal in multiple rows.
   </para>
 
   <para>