Thread: order of checking the unique constraints
Using 9.1
Can somebody tell me the order in which the Unique Constraints of a table are checked, like when an INSERT is done ?
It seems the the Primary is checked first, but what about the regular UCs ?
Thanks,
-dvs-
Hello,
I had a similar question some time ago, with an answer by Tom lane:
http://archives.postgresql.org/pgsql-general/2012-03/msg00023.php
best regards,
Marc Mamin
From: pgsql-general-owner@postgresql.org [mailto:pgsql-general-owner@postgresql.org] On Behalf Of Sahagian, David
Sent: Dienstag, 28. August 2012 15:46
To: pgsql-general@postgresql.org
Subject: [GENERAL] order of checking the unique constraints
Using 9.1
Can somebody tell me the order in which the Unique Constraints of a table are checked, like when an INSERT is done ?
It seems the the Primary is checked first, but what about the regular UCs ?
Thanks,
-dvs-
>> Can somebody tell me the order in which the Unique Constraints of a table >> are checked, like when an INSERT is done ? > > I had a similar question some time ago, with an answer by Tom lane: > http://archives.postgresql.org/pgsql-general/2012-03/msg00023.php You might also find interesting that this behavior can be controlled by specifying DEFERRABLE/IMEDIATE properties on your UCs and by using SET CONSTRAINTS dirrective. http://www.postgresql.org/docs/9.1/interactive/sql-set-constraints.html -- Sergey Konoplev a database and software architect http://www.linkedin.com/in/grayhemp Jabber: gray.ru@gmail.com Skype: gray-hemp Phone: +79160686204