From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Bruce Momjian <bruce@momjian.us>
Cc: Mladen Gogala <mladen.gogala@vmsinfo.com>
Cc: Greg Smith <greg@2ndquadrant.com>
Cc: Andrew Dunstan <andrew@dunslane.net>
Cc: david@lang.hm <david@lang.hm>
Cc: Craig Ringer <craig@postnewspapers.com.au>
Cc: Vitalii Tymchyshyn <tivv00@gmail.com>
Cc: pgsql-performance@postgresql.org <pgsql-performance@postgresql.org>
Subject: Re: [HACKERS] Slow count(*) again...
Date: Thu, 03 Feb 2011 12:46:48 -0500
Message-ID: <25146.1296755208@sss.pgh.pa.us> (raw)
In-Reply-To: <AANLkTi=rfLJwboH7r3kXvDHmn2vJU1wr8YK+mUJfRdy1@mail.gmail.com>
References: <4D4AD9F6.6040903@vmsinfo.com>
<201102031656.p13Guug09499@momjian.us>
<AANLkTi=rfLJwboH7r3kXvDHmn2vJU1wr8YK+mUJfRdy1@mail.gmail.com>
Robert Haas <robertmhaas@gmail.com> writes:
> I don't, however, agree with his contention that this is easy to
> implement. It would be easy to implement something that sucked. It
> would be hard to implement something that actually helped in the cases
> where the existing settings aren't already sufficient.
Exactly. A hint system that actually did more good than harm would be a
very nontrivial project. IMO such effort is better spent on making the
optimizer smarter.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, robertmhaas@gmail.com, bruce@momjian.us, mladen.gogala@vmsinfo.com, greg@2ndquadrant.com, andrew@dunslane.net, david@lang.hm, craig@postnewspapers.com.au, tivv00@gmail.com
Subject: Re: [HACKERS] Slow count(*) again...
In-Reply-To: <25146.1296755208@sss.pgh.pa.us>
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