Re: Row versions and indexes

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От Alan Hodgson
Тема Re: Row versions and indexes
Дата
Msg-id 200609281506.49687@hal.medialogik.com
обсуждение исходный текст
Ответ на Row versions and indexes  ("Jack Orenstein" <jack.orenstein@gmail.com>)
Список pgsql-general
On Thursday 28 September 2006 14:58, "Jack Orenstein"
<jack.orenstein@gmail.com> wrote:
> How does versioning work for the index?
>
> - The update above does not update the index key. Does the index get
>   updated at all?
>

Yes, it does.

> - If not, then how can an index lookup return the correct version of
>   selected rows?
>
> This aspect of versioning has never been clear to me. Now there's a cost
> issue involved, as I need to update every row in a large table, never
> updating the index key. Will this run faster if I drop the index?
> (Yes, I can run the experiment, but I'd like to understand the
> fundamentals better.)

Yes, it certainly will.

--
"A government that robs Peter to pay Paul can always depend upon the support
of Paul." - George Bernard Shaw


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