From: Tom Lane <tgl@sss.pgh.pa.us>
To: Martijn van Oosterhout <kleptog@svana.org>
Cc: Ron Peacetree <rjpeace@earthlink.net>
Cc: pgsql-hackers@postgresql.org
Subject: Re: [PERFORM] A Better External Sort?
Date: Sat, 01 Oct 2005 23:26:07 -0400
Message-ID: <29837.1128223567@sss.pgh.pa.us> (raw)
In-Reply-To: <20051001215602.GG13830@svana.org>
References: <18329659.1128188552696.JavaMail.root@elwamui-polski.atl.sa.earthlink.net>
<20051001215602.GG13830@svana.org>
Martijn van Oosterhout <kleptog@svana.org> writes:
> Anyway, to bring some real info I just profiled PostgreSQL 8.1beta
> doing an index create on a 2960296 row table (3 columns, table size
> 317MB).
3 columns in the index you mean? What were the column datatypes?
Any null values?
> The number 1 bottleneck with 41% of user time is comparetup_index.
> ...
> The thing is, I can't see anything in comparetup_index() that could
> take much time.
The index_getattr and heap_getattr macros can be annoyingly expensive.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, kleptog@svana.org, rjpeace@earthlink.net, pgsql-hackers@postgresql.org
Subject: Re: [PERFORM] A Better External Sort?
In-Reply-To: <29837.1128223567@sss.pgh.pa.us>
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