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
This commit is contained in:
Robert Haas 2017-03-27 11:01:33 -04:00
parent 4785e377f9
commit d65561464f
1 changed files with 7 additions and 2 deletions

View File

@ -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>