From d65561464f45d325e82ad91918bcd4e2881ce567 Mon Sep 17 00:00:00 2001
From: Robert Haas <rhaas@postgresql.org>
Date: Mon, 27 Mar 2017 11:01:33 -0400
Subject: [PATCH] Improve documentation of how NOT NULL works with
partitioning.
Amit Langote
Discussion: http://postgr.es/m/a6f99cdb-21e7-1d65-1381-91f2cfa156e2@lab.ntt.co.jp
---
doc/src/sgml/ref/alter_table.sgml | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml
index 75de2262539..7829f378bba 100644
--- a/doc/src/sgml/ref/alter_table.sgml
+++ b/doc/src/sgml/ref/alter_table.sgml
@@ -175,9 +175,14 @@ ALTER TABLE [ IF EXISTS ] <replaceable class="PARAMETER">name</replaceable>
</para>
<para>
- If this table is a partition, one cannot perform <literal>DROP NOT NULL</>
+ If this table is a partition, one cannot perform <literal>DROP NOT NULL</literal>
on a column if it is marked <literal>NOT NULL</literal> in the parent
- table.
+ table. To drop the <literal>NOT NULL</literal> constraint from all the
+ partitions, perform <literal>DROP NOT NULL</literal> on the parent
+ table. Even if there is no <literal>NOT NULL</> constraint on the
+ parent, such a constraint can still be added to individual partitions,
+ if desired; that is, the children can disallow nulls even if the parent
+ allows them, but not the other way around.
</para>
</listitem>
</varlistentry>
--
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