Re: Index Scans become Seq Scans after VACUUM ANALYSE

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От Michael Loftis
Тема Re: Index Scans become Seq Scans after VACUUM ANALYSE
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Msg-id 3CBD8584.8040200@wgops.com
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Ответ на Re: Index Scans become Seq Scans after VACUUM ANALYSE  (Bruce Momjian <pgman@candle.pha.pa.us>)
Ответы Re: Index Scans become Seq Scans after VACUUM ANALYSE  (Bruce Momjian <pgman@candle.pha.pa.us>)
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Thomas Lockhart wrote:

>
>Systems which have optimizing planners can *never* be guaranteed to
>generate the actual lowest-cost query plan. Any impression that Oracle,
>for example, actually does do that may come from a lack of visibility
>into the process, and a lack of forum for discussing these edge cases.
>
I wholly agree...  Oracle has some fairly *sick* ideas at times about 
what to do in the face of partial ambiguity.  (I've got a small set of 
queries that will drive any machine with PeopleSoft DBs loaded to near 
catatonia...) :)

As far as the 'planner benchmark suite' so we cans tart gathering more 
statistical data about what costs should be, or are better at, that's an 
excellent idea.



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