To: pgsql-sql@postgresql.org
From: Jasen Betts <jasen@xnet.co.nz>
Subject: Re: Order of evaluation in triggers for checks on inherited table
	partitions
Date: 30 May 2011 09:21:19 GMT
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On 2011-05-27, Kevin Crain <kevin.crain1@gmail.com> wrote:
> I am trying to create a trigger on updates to a table that is
> partitioned.  The child tables are partitioned by month and include
> checks on a timestamp field. 

> However when I try to update an existing record with a
> timestamp that would place it in a child table different from the
> child table it is in I get an error due to the check on the child
> table it is currently in.  My best guess as to what is happening is
> that the trigger is evaluating the check before it evaluates the
> trigger function and thus cannot tell that the update to the original
> table should never take place.  I have included an example below.  The
> error that results is "new row for relation "t_foo_2011_6" violates
> check constraint "t_foo_2011_6_f_timestamp_check""

the problem is the check is running before the trigger.
perhaps you can use a rule instead of a trigger?

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