Re: SELECT performance drop v 6.5 -> 7.0.3

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От Joseph Shraibman
Тема Re: SELECT performance drop v 6.5 -> 7.0.3
Дата
Msg-id 3AA702F8.1EA531DF@selectacast.net
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Ответ на RE: SELECT performance drop v 6.5 -> 7.0.3  ("Creager, Robert S" <CreagRS@LOUISVILLE.STORTEK.COM>)
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"Creager, Robert S" wrote:
>
> I've a question.  I have often seen the 'trick' of dropping an index,
> importing large amounts of data, then re-creating the index to speed the
> import.  The obvious problem with this is during the time from index drop to
> the index finishing re-creation, a large db is going to be essentially
> worthless to queries which use those indexes.  I know nothing about the
> backend and how it does 'stuff', so I may be asking something absurd here.
> Why, when using transactions, are indexes updated on every insert?  It seems
> logical (to someone who doesn't know better), that the indexes could be
> updated on the COMMIT.
>
> Please don't hurt me too bad...
> Rob
>

I imagine because the transaction might do a select on data it just
inserted/updated.

--
Joseph Shraibman
jks@selectacast.net
Increase signal to noise ratio.  http://www.targabot.com

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