From: Jeroen van Iddekinge <iddekingej@lycos.com>
To: pgsql-performance@postgresql.org
Subject: sequence scan on PK
Date: Sun, 08 May 2005 14:59:13 +0000
Message-ID: <427E2941.9070105@lycos.com> (raw)
Hi,
I understand that when a table contains only a few rows it is better to
do a sequence scan than an index scan. But is this also for a table with
99 records?
A table contains
id integer (primary key)
name varchar(70)
parent integer
comment text
owner integer
inheritAccess integer
defaultAccess integer
sequence bigint
contentsinheritaccessmove integer
contentsinheritaccessadd integer
explain select * from tblFolders where id=90;
QUERY PLAN
-----------------------------------------------------------
Seq Scan on tblfolders (cost=0.00..3.24 rows=1 width=50)
Filter: (id = 90)
(I have analyze table bit still a sequence scan).
With how manys rows it is ok to do an index scan or sequence scan? How
is this calculated in pg?
Regards
Jer
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To: pgsql-performance@postgresql.org
Cc: iddekingej@lycos.com
Subject: Re: sequence scan on PK
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