Re: SELECT statement returns in 10seconds, but INSERT/CREATE TABLEAS with same SELECT takes 7 minutes

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От Justin Pryzby
Тема Re: SELECT statement returns in 10seconds, but INSERT/CREATE TABLEAS with same SELECT takes 7 minutes
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Msg-id 20180928001208.GL776@telsasoft.com
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Ответ на Re: SELECT statement returns in 10seconds, but INSERT/CREATE TABLE ASwith same SELECT takes 7 minutes  (Vladimir Ryabtsev <greatvovan@gmail.com>)
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On Thu, Sep 27, 2018 at 04:50:36PM -0700, Vladimir Ryabtsev wrote:
> Additionally, I think author can try CREATE STATISTICS on the bunch of
> columns used in join. Very low rows estimate for this join may come from
> multiplying selectivities for each column assuming they are independent.

MV statistics don't currently help for joins:

https://www.postgresql.org/message-id/flat/CAKJS1f-6B7KnDFrh6SFhYn-YbHYOXmDDAfd0XC%3DjJKZMCrfQyg%40mail.gmail.com#925e19951fabc9a480b804d661d83be8

Justin

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