From: Craig Ringer <craig@postnewspapers.com.au>
To: Lutischán Ferenc <lutischanf@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Improve Seq scan performance
Date: Mon, 10 Nov 2008 15:55:55 +0900
Message-ID: <4917DAFB.8000003@postnewspapers.com.au> (raw)
In-Reply-To: <4917D9C3.9060001@gmail.com>
References: <4917D9C3.9060001@gmail.com>
Lutischán Ferenc wrote:
> It is possible to make an index on the table, and make a seq index scan
> on this values?
My understanding is that this isn't possible in PostgreSQL, because
indexes do not contain information about tuple visibility. Data read
from the index might refer to tuples that've been deleted as far as your
transaction is concerned, or to tuples that were created after your
snapshot was taken.
--
Craig Ringer
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To: pgsql-performance@postgresql.org
Cc: craig@postnewspapers.com.au, lutischanf@gmail.com
Subject: Re: Improve Seq scan performance
In-Reply-To: <4917DAFB.8000003@postnewspapers.com.au>
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