From: Tom Lane <tgl@sss.pgh.pa.us>
To: sebaioni-postgresql@yahoo.com.ar
Cc: Performance PostgreSQL <pgsql-performance@postgresql.org>
Subject: Re: Inner Join of the same table
Date: Tue, 15 Aug 2006 17:13:02 -0400
Message-ID: <20384.1155676382@sss.pgh.pa.us> (raw)
In-Reply-To: <20060815185335.14227.qmail@web36114.mail.mud.yahoo.com>
References: <20060815185335.14227.qmail@web36114.mail.mud.yahoo.com>
=?iso-8859-1?q?Sebasti=E1n=20Baioni?= <sebaioni-postgresql@yahoo.com.ar> writes:
> 8 -> GroupAggregate (cost=0.00..37348395.05 rows=3951 width=25) (actual
> time=130.000..2629617.000 rows=254576 loops=1)
> 9 -> Index Scan using uesapt001 on APORTES (cost=0.00..37301678.64
> rows=9339331 width=25) (actual time=110.000..2520690.000 rows=9335892 loops=1)
Given the relatively small estimated number of group rows, I'd have
expected the thing to use a seqscan and HashAggregate for this part.
Do you have enable_hashagg turned off for some reason? Or enable_seqscan?
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, sebaioni-postgresql@yahoo.com.ar
Subject: Re: Inner Join of the same table
In-Reply-To: <20384.1155676382@sss.pgh.pa.us>
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