From: Tom Lane <tgl@sss.pgh.pa.us>
To: Steinar H. Gunderson <sgunderson@bigfoot.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Performance pb vs SQLServer.
Date: Sun, 14 Aug 2005 21:18:45 -0400
Message-ID: <14401.1124068725@sss.pgh.pa.us> (raw)
In-Reply-To: <20050815010159.GA27795@uio.no>
References: <20050811131911.3175A1C0031B@mwinf0401.wanadoo.fr>
<42FFE17A.6010208@arbash-meinel.com>
<20050815010159.GA27795@uio.no>
"Steinar H. Gunderson" <sgunderson@bigfoot.com> writes:
> To me, it looks like he'll get 88 rows, not 3.2M. Surely we must be able to
> do something better than a full sequential scan in this case?
Not really. There's been some speculation about implementing index
"skip search" --- once you've verified there's at least one visible
row of a given index value, tell the index to skip to the next different
value instead of handing back any of the remaining entries of the
current value. But it'd be a lot of work and AFAICS not useful for
very many kinds of queries besides this.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, sgunderson@bigfoot.com
Subject: Re: Performance pb vs SQLServer.
In-Reply-To: <14401.1124068725@sss.pgh.pa.us>
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