Re: Is this expected? (Index scanning)

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От Mitch Vincent
Тема Re: Is this expected? (Index scanning)
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Msg-id 000701c0d6a8$27924100$1251000a@windows
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Ответ на Re: Is this expected? (Index scanning)  (Stephan Szabo <sszabo@megazone23.bigpanda.com>)
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> In the first and last case the like is anchored at the beginning so it
> uses the name index.  The middle case can't use that index, and how
> well distributed are the values of void (is it a boolean?)?

Ahh... I thought that the middle case could use an index, I guess that's why
I was confused..

>It's likely
> that the index isn't very selective, if most of the rows are void='f'
> then that index is probably more expensive to scan than the sequence scan
> would be.

Yep, most of the rows are void='f'..

Thanks!!

-Mitch



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