Re: Confusing performance of specific query - Mailing list pgsql-general

From Tom Lane
Subject Re: Confusing performance of specific query
Date
Msg-id 11587.1186724848@sss.pgh.pa.us
Whole thread Raw
In response to Re: Confusing performance of specific query  (Adam Endicott <leftwing17@gmail.com>)
Responses Re: Confusing performance of specific query  (Adam Endicott <leftwing17@gmail.com>)
List pgsql-general
Adam Endicott <leftwing17@gmail.com> writes:
> Here's the output from explain analyze.

Wow, so the differential is all in the sort step.

8.2 does have improved sorting code, but I don't think that explains
the difference, especially not for a mere 16000 rows to be sorted.

Do you have comparable work_mem settings on both machines?  Another
thing to look at, if any of the sort key columns are textual, is whether
the lc_collate settings are the same.

            regards, tom lane

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