Re: ??: Postgresql update op is very very slow

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От Andrew Sullivan
Тема Re: ??: Postgresql update op is very very slow
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Msg-id 20080626135501.GF6918@commandprompt.com
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Ответ на Re: ??: Postgresql update op is very very slow  (Craig Ringer <craig@postnewspapers.com.au>)
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On Thu, Jun 26, 2008 at 09:16:25PM +0800, Craig Ringer wrote:

> I think Pg already does in place updates, or close, if the tuples being
> replaced aren't referenced by any in-flight transaction. I noticed a while
> ago that if I'm doing bulk load/update work, if there aren't any other
> transactions no MVCC bloat seems to occur and updates are faster.

Are you on 8.3?  That may be HOT working for you.  MVCC doesn't get
turned off if there are no other transactions (it can't: what if
another transaction starts part way through yours?).

A

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