Re: Update join performance issues

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От Andrew Dunstan
Тема Re: Update join performance issues
Дата
Msg-id 4F7B35B9.50108@dunslane.net
обсуждение исходный текст
Ответ на Update join performance issues  (Kevin Kempter <cs_dba@consistentstate.com>)
Ответы Re: Update join performance issues  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
Список pgsql-performance

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




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