order of checking the unique constraints

Started by Sahagian, Davidover 13 years ago3 messagesgeneral
Jump to latest
#1Sahagian, David
david.sahagian@emc.com

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-

#2Marc Mamin
M.Mamin@intershop.de
In reply to: Sahagian, David (#1)
Re: order of checking the unique constraints

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-

#3Sergey Konoplev
gray.ru@gmail.com
In reply to: Marc Mamin (#2)
Re: order of checking the unique constraints

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