Re: A query planner that learns

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От Jim C. Nasby
Тема Re: A query planner that learns
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Msg-id 20061013175101.GH28647@nasby.net
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Ответ на Re: A query planner that learns  (AgentM <agentm@themactionfaction.com>)
Ответы Re: A query planner that learns  ("Guy Rouillier" <guyr@masergy.com>)
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On Fri, Oct 13, 2006 at 11:53:15AM -0400, AgentM wrote:
> One simple first step would be to run an ANALYZE whenever a
> sequential scan is executed. Is there a reason not to do this? It

Yes. You want a seqscan on a small (couple pages) table, and ANALYZE has
a very high overhead on some platforms.

Just recording the query plan and actual vs estimated rowcounts would be
a good start, though. And useful to DBA's, provided you had some means
to query against it.
--
Jim Nasby                                            jim@nasby.net
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)

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