Re: [HACKERS] nested loops in joins, ambiguous rewrite rules

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От Bruce Momjian
Тема Re: [HACKERS] nested loops in joins, ambiguous rewrite rules
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Msg-id 199901311935.OAA07665@candle.pha.pa.us
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Ответ на Re: [HACKERS] nested loops in joins, ambiguous rewrite rules  (Tom Lane <tgl@sss.pgh.pa.us>)
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> Perhaps if we develop a slightly more complex measure to compare against
> the GEQO threshold, we can do better in deciding when to kick in GEQO.
> A brain-dead suggestion is number of tables + number of indexes ...
> does anyone know whether that is a good measure of the number of cases
> considered in the optimizer?

That is an excellent suggestion.  We have always seen 6-table joins that
are short with geqo, and some longer.  Perhaps that is the cause.

--  Bruce Momjian                        |  http://www.op.net/~candle maillist@candle.pha.pa.us            |  (610)
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