Horton

Re: Index Scans become Seq Scans after VACUUM ANALYSE

Christopher Kings-Lynne <chriskl@familyhealth.com.au>

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From: "Christopher Kings-Lynne" <chriskl@familyhealth.com.au>
To: "Thomas Lockhart" <thomas@fourpalms.org>, "mlw" <markw@mohawksoft.com>
Cc: "Tom Lane" <tgl@sss.pgh.pa.us>, "Bruce Momjian" <pgman@candle.pha.pa.us>, "Louis-David Mitterrand" <vindex@apartia.org>, <pgsql-hackers@postgresql.org>
Date: 2002-04-17T14:56:20Z
Lists: pgsql-hackers 
> 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.

Hmmm...with PREPARE and EXECUTE, would it be possible to somehow get the
planner to actually run a few different selects and then actually store the
actual fastest plan?  I'm being very fanciful here, of course...

Chris