From: Tom Lane <tgl@sss.pgh.pa.us>
To: Jeffrey Tenny <jeffrey.tenny@comcast.net>
Cc: Jim C. Nasby <jnasby@pervasive.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: performance question (something to do w/ parameterized
Date: Mon, 08 May 2006 19:06:01 -0400
Message-ID: <2398.1147129561@sss.pgh.pa.us> (raw)
In-Reply-To: <445FC215.8070804@comcast.net>
References: <445F7FF8.6070707@comcast.net>
<20060508173812.GW99570@pervasive.com>
<445F9F6B.9040200@comcast.net>
<29345.1147118920@sss.pgh.pa.us>
<445FAB2A.9050401@comcast.net>
<29684.1147121398@sss.pgh.pa.us>
<445FC215.8070804@comcast.net>
Jeffrey Tenny <jeffrey.tenny@comcast.net> writes:
> I tried the seqscan disabling and got what sounds like the desired plan:
> Sort (cost=54900.62..54940.29 rows=1587 width=16) (actual time=20.208..22.138 rows=677 loops=1)
> Sort Key: f, c
> -> Index Scan using x_f_idx, x_f_idx, ...
> (cost=0.00..54056.96 rows=1587 width=16) (actual time=1.048..15.598 rows=677 loops=1)
> Index Cond: ((f = 1) OR (f = 2) OR (f = 3) ....
Hm, vs 35000 or so estimates for the slower plans. My recommendation
would be to decrease random_page_cost to 2 or so, instead of the brute
force disable-seqscans approach.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, jeffrey.tenny@comcast.net, jnasby@pervasive.com
Subject: Re: performance question (something to do w/ parameterized
In-Reply-To: <2398.1147129561@sss.pgh.pa.us>
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