Date: Sat, 20 Oct 2007 19:19:39 +0200
From: Andreas Kretschmer <akretschmer@spamfence.net>
To: pgsql-performance@postgresql.org, pgsql-sql@postgresql.org
Subject: Re: [SQL] two queryes in a single tablescan
Message-ID: <20071020171938.GA24518@KanotixBox>
References: <290a5abc0710170530v215cb2b0q4fa000ad43096a28@mail.gmail.com>
	<20071020125824.75df357c@kingfisher.sec.intern.logix-tt.com>
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Markus Schaber <schabi@logix-tt.com> schrieb:
> > is there any way to get both results in a single query,
> > eventually through stored procedure?
> > The retrieved [count(*),A] ; [count(*),B)] data couldnt fit
> > on a single table, of course.
> > 
> > The main goal would be to get multiple results while scanning the
> > table[s] once only
> > thus getting results in a faster  way.
> 
> PostgreSQL 8.3 contains great improvements in this area, you can simply
> start the selects from concurrent connections, and the backend will
> synchronize the scans.

works this right across different transactions? I mean, for instance, TX
a insert rows and TX b insert other rows and both clients (with
different transactions) starts a seq-scan?


Andreas
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