Re: postgres FROM clause problem - Mailing list pgsql-general

From Tom Lane
Subject Re: postgres FROM clause problem
Date
Msg-id 21179.1079027627@sss.pgh.pa.us
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In response to Re: postgres FROM clause problem  (Paolo Tavalazzi <ptavalazzi@charta.it>)
Responses Re: postgres FROM clause problem
List pgsql-general
Paolo Tavalazzi <ptavalazzi@charta.it> writes:
> [ query plans after updating to 7.4.2 ]

Okay, they're certainly a lot closer than before, so I think I was right
that you were getting bitten somehow by the pg_statistic alignment
problem.  It seems like there may still be a bug lurking though.  The
rows-out estimates are 7 versus 9 for the middle nested-loop join.
That might just be roundoff error, or there may be something else going
on.  Also the estimates for the top join are 7 versus 1 rows, which
seems too large a ratio to be explainable as roundoff error.

Could I pester you to send me a pg_dump dump of this database off-list?
I'd like to trace through the planner with a debugger and see exactly
where the results are diverging.

            regards, tom lane

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