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Re: select count(*) and limit - Mailing list pgsql-novice

From Verena Ruff
Subject Re: select count(*) and limit
Date
Msg-id 446CA0AF.1000001@triosolutions.at
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In response to Re: select count(*) and limit  (Sean Davis <sdavis2@mail.nih.gov>)
Responses Re: select count(*) and limit
List pgsql-novice
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Hi,

Sean Davis schrieb:
> It should still work just fine, again with the caveat that it is an
> approximation and depends on the statistics available.  Try comparing the
> output a few times for your count(*) and using EXPLAIN.
>
sometimes the difference is to much to go this way. EXPLAIN extimates
71000 rows but there are 95000. 10% would have been accaptle. I did
these tests on a freshly vacuumed database.

regards,
Verena

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