Re: add_path optimization - Mailing list pgsql-hackers

From Jaime Casanova
Subject Re: add_path optimization
Date
Msg-id 3073cc9b0902011034q988d13fxe41f3d0f30a0d891@mail.gmail.com
Whole thread Raw
In response to add_path optimization  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: add_path optimization  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
On Sat, Jan 31, 2009 at 11:37 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> I've been doing some benchmarking and profiling on the PostgreSQL
> query analyzer, and it seems that (at least for the sorts of queries
> that I typically run) the dominant cost is add_path().  I've been able
> to find two optimizations that seem to help significantly:
>
> 1. add_path() often calls compare_fuzzy_path_costs() twice on the same
>
> 2. match_unsorted_outer() adds as many as 5 nested loop joins at a

if there are two optimizations maybe two different patches are better
to test them individually

--
Atentamente,
Jaime Casanova
Soporte y capacitación de PostgreSQL
Asesoría y desarrollo de sistemas
Guayaquil - Ecuador
Cel. +59387171157


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