Re: Sort time

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От Josh Berkus
Тема Re: Sort time
Дата
Msg-id 200211151127.29405.josh@agliodbs.com
обсуждение исходный текст
Ответ на Re: Sort time  (Rod Taylor <rbt@rbt.ca>)
Ответы Re: Sort time
Список pgsql-performance
Rod,

> The estimated cost had the sort at a few seconds, but the actual times
> show it is taking 50% of the total query time.

D'oh!   I was, of course, subtracting the estimated from the actual time.
Oops.

>
> The big problem is he's sorting by a varchar() which isn't overly quick
> no matter what locale.  Integers are nice and quick (s.OP is an int,
> which shows this).
>
> If IDS_NUM is a number, he could try casting it to an int8, but without
> data examples I couldn't say.

Hmmm ... how big *is* that varchar field?  8 characters gives us about 6mb for
the column.  Of course, if it's a 128-char global unque id, that;s a bit
larger.

--
-Josh Berkus

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