Re: [despammed] question about index

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От Bruno Wolff III
Тема Re: [despammed] question about index
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Msg-id 20041216141025.GC2768@wolff.to
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Ответ на Re: [despammed] question about index  (Andreas Kretschmer <akretschmer@despammed.com>)
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On Thu, Dec 16, 2004 at 12:01:39 +0100, Andreas Kretschmer <akretschmer@despammed.com> wrote:
> > 
> > considering that almost 70% of the rows will be with 'VALUE1', 20%
> > will be with 'VALUE2' and 10% will be with 'VALUE3' on the average.
> > 
> > should I create an index to speedup the counts or not ?
> 
> Yes.

Indexes will probably not help in this case. Even when looking at 10% of
the rows, a sequential scan is still going to be faster than an index
scan in most cases.


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