Re: BUG #2953: index scan, feature request

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От Tom Lane
Тема Re: BUG #2953: index scan, feature request
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Msg-id 13719.1170382671@sss.pgh.pa.us
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Ответ на BUG #2953: index scan, feature request  ("michael" <miblogic@yahoo.com>)
Ответы Re: BUG #2953: index scan, feature request  (Magnus Hagander <magnus@hagander.net>)
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"michael" <miblogic@yahoo.com> writes:
> can these be executed with index seek like what MS SQL does?
> select * from account_category
> where account_category_full_description <> 'MICHAEL'

What for?  A query like that is generally going to fetch the majority of
the table, so an indexscan would be counterproductive.

It could potentially be a win if a very large fraction of the rows had
the exact value MICHAEL ... but the recommended way to deal with that is
to create a partial index with "full_description <> 'MICHAEL'" as the
WHERE clause.

            regards, tom lane

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