From: Emil Briggs <emil@baymountain.com>
To: John A Meinel <john@arbash-meinel.com>
Cc: Postgresql Performance <pgsql-performance@postgresql.org>
Subject: Re: Planner constants for RAM resident databases
Date: Sat, 2 Jul 2005 09:44:07 -0400
Message-ID: <200507020944.07339.emil@baymountain.com> (raw)
In-Reply-To: <42C606AA.8060406@arbash-meinel.com>
References: <200507012159.39041.emil@baymountain.com>
<200507012311.37942.emil@baymountain.com>
<42C606AA.8060406@arbash-meinel.com>
> When you do "explain analyze" of a query that you have difficulties
> with, how are the planner's estimates. Are the estimated number of rows
> about equal to the actual number of rows?
Some of them are pretty far off. For example
-> Merge Left Join (cost=9707.71..13993.52 rows=1276 width=161) (actual
time=164.423..361.477 rows=49 loops=1)
I tried setting enable_merge_joins to off and that made the query about three
times faster. It's using a hash join instead.
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To: pgsql-performance@postgresql.org
Cc: emil@baymountain.com, john@arbash-meinel.com
Subject: Re: Planner constants for RAM resident databases
In-Reply-To: <200507020944.07339.emil@baymountain.com>
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