From: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Peter Geoghegan <peter@2ndquadrant.com>
Cc: Stefan Keller <sfkeller@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Hash index use presently(?) discouraged since 2005: revive or bury it?
Date: Wed, 14 Sep 2011 12:03:58 +0300
Message-ID: <4E706DFE.40801@enterprisedb.com> (raw)
In-Reply-To: <16096.1315959870@sss.pgh.pa.us>
References: <CAFcOn293Rzi7cZYWBT8tjxCtNX5pYdbknANXgf9mWfBizK8Frg@mail.gmail.com>
<CAEYLb_Udue8_XSE9K0KMqKBE_62yurv1bY4Wc+qJoGykZ_rXtA@mail.gmail.com>
<16096.1315959870@sss.pgh.pa.us>
On 14.09.2011 03:24, Tom Lane wrote:
> The big picture though is that we're not going to remove hash indexes,
> even if they're nearly useless in themselves, because hash index
> opclasses provide the foundation for the system's knowledge of how to
> do the datatype-specific hashing needed for hash joins and hash
> aggregation. And those things *are* big wins, even if hash indexes
> themselves never become so.
We could drop the hash indexam code but keep the opclasses etc. I'm not
sure that would gain us, though.
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com
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To: pgsql-performance@postgresql.org
Cc: heikki.linnakangas@enterprisedb.com, tgl@sss.pgh.pa.us, peter@2ndquadrant.com, sfkeller@gmail.com
Subject: Re: Hash index use presently(?) discouraged since 2005: revive or bury it?
In-Reply-To: <4E706DFE.40801@enterprisedb.com>
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