Re: bitmap-index-scan slower than normal index scan

От: A. Kretschmer
Тема: Re: bitmap-index-scan slower than normal index scan
Дата: ,
Msg-id: 20070712050631.GA2729@a-kretschmer.de
(см: обсуждение, исходный текст)
Ответ на: Re: bitmap-index-scan slower than normal index scan  (Andreas Kretschmer)
Список: pgsql-performance

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bitmap-index-scan slower than normal index scan  (Andreas Kretschmer, )
 Re: bitmap-index-scan slower than normal index scan  ("Alex Deucher", )
  Re: bitmap-index-scan slower than normal index scan  ("A. Kretschmer", )
   Re: bitmap-index-scan slower than normal index scan  ("Alex Deucher", )
    Re: bitmap-index-scan slower than normal index scan  ("Alex Deucher", )
 Re: bitmap-index-scan slower than normal index scan  (Tom Lane, )
  Re: bitmap-index-scan slower than normal index scan  (Andreas Kretschmer, )
   Re: bitmap-index-scan slower than normal index scan  ("A. Kretschmer", )

am  Wed, dem 11.07.2007, um 22:19:58 +0200 mailte Andreas Kretschmer folgendes:
> > Also, part of the problem here looks to be an overestimate of the number
> > of rows matching ab = 347735.  It might help to increase the statistics
> > target for that column.
>
> I will try this tomorrow and inform you about the result. I've never
> done this before, i need to read the docs about this.

Okay, done, setting to 100 (thanks to mastermind) and now i got an Index
Scan using idx_ab with a total runtime: 0.330 ms.

Great, thanks. And yes, i will update soon...


Andreas
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