Re: [SQL] two queryes in a single tablescan

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От Andreas Kretschmer
Тема Re: [SQL] two queryes in a single tablescan
Дата
Msg-id 20071020171938.GA24518@KanotixBox
обсуждение исходный текст
Ответ на Re: [SQL] two queryes in a single tablescan  (Markus Schaber <schabi@logix-tt.com>)
Ответы Re: [SQL] two queryes in a single tablescan  (Erik Jones <erik@myemma.com>)
Список 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
--
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