Re: [SQL] two queryes in a single tablescan - Mailing list pgsql-performance

From Andreas Kretschmer
Subject Re: [SQL] two queryes in a single tablescan
Date
Msg-id 20071020171938.GA24518@KanotixBox
Whole thread Raw
In response to Re: [SQL] two queryes in a single tablescan  (Markus Schaber <schabi@logix-tt.com>)
Responses Re: [SQL] two queryes in a single tablescan
List pgsql-performance
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
--
Really, I'm not out to destroy Microsoft. That will just be a completely
unintentional side effect.                              (Linus Torvalds)
"If I was god, I would recompile penguin with --enable-fly."    (unknow)
Kaufbach, Saxony, Germany, Europe.              N 51.05082°, E 13.56889°

pgsql-performance by date:

Previous
From: Markus Schaber
Date:
Subject: Re: [SQL] two queryes in a single tablescan
Next
From: Pavel Velikhov
Date:
Subject: Re: need help with a query