From: Simon Riggs <simon@2ndquadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Balazs Nagy <bnagy@thenewpush.com>
Cc: pgsql-bugs@postgresql.org
Cc: pgsql-performance@postgresql.org
Subject: Re: [PERFORM] BUG #2737: hash indexing large table fails, while btree of same index works
Date: Sat, 11 Nov 2006 08:17:54 +0000
Message-ID: <1163233075.3634.944.camel@silverbirch.site> (raw)
In-Reply-To: <7530.1163202951@sss.pgh.pa.us>
References: <200611051347.kA5DlVCk032222@wwwmaster.postgresql.org>
<7530.1163202951@sss.pgh.pa.us>
On Fri, 2006-11-10 at 18:55 -0500, Tom Lane wrote:
> [ cc'ing to pgsql-performance because of performance issue for hash indexes ]
>
> "Balazs Nagy" <bnagy@thenewpush.com> writes:
> > Database table size: ~60 million rows
> > Field to index: varchar 127
>
> > CREATE INDEX ... USING hash ...
I'd be interested in a performance test that shows this is the best way
to index a table though, especially for such a large column. No wonder
there is an 8GB index.
> One thought that comes to mind is to require hash to do an smgrextend()
> addressing the last block it intends to use whenever it allocates a new
> batch of blocks, whereupon md.c could adopt a saner API: allow
> smgrextend but not other calls to address blocks beyond the current EOF.
> Thoughts?
Yes, do it.
--
Simon Riggs
EnterpriseDB http://www.enterprisedb.com
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To: pgsql-performance@postgresql.org
Cc: simon@2ndquadrant.com, tgl@sss.pgh.pa.us, bnagy@thenewpush.com, pgsql-bugs@postgresql.org
Subject: Re: [PERFORM] BUG #2737: hash indexing large table fails, while btree of same index works
In-Reply-To: <1163233075.3634.944.camel@silverbirch.site>
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