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Message-ID: <4F7B35B9.50108@dunslane.net>
Date: Tue, 03 Apr 2012 13:39:05 -0400
From: Andrew Dunstan <andrew@dunslane.net>
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To: Kevin Kempter <cs_dba@consistentstate.com>
CC: "pgsql-performance@postgresql.org" <pgsql-performance@postgresql.org>
Subject: Re: Update join performance issues
References: <4F7B3394.3030703@consistentstate.com>
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On 04/03/2012 01:29 PM, Kevin Kempter wrote:
> Hi All;
>
> I have a query that wants to update a table based on a join like this:
>
> update test_one
> set f_key = t.f_key
> from
>     upd_temp1 t,
>     test_one t2
> where
>     t.id_number = t2.id_number


Why is test_one in the from clause? update joins whatever is in the from 
clause to the table being updated. You almost never need it repeated in 
the from clause.


cheers

andrew