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Re: add_path optimization

From: Jaime Casanova <jcasanov(at)systemguards(dot)com(dot)ec>
To: Robert Haas <robertmhaas(at)gmail(dot)com>
Cc: "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: add_path optimization
Date: 2009-02-01 18:34:51
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-hackers
On Sat, Jan 31, 2009 at 11:37 PM, Robert Haas <robertmhaas(at)gmail(dot)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

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

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