Re: PostgreSQL performance issues

am Tue, dem 29.08.2006, um 16:55:11 +0200 mailte Willo van der Merwe folgendes:
> >>4 1/2 seconds for a count(*) ? This seems a bit rough - is there anything
> >>else
> >>
> >
> >Because of MVCC.
> >http://www.thescripts.com/forum/thread173678.html
> >http://www.varlena.com/GeneralBits/120.php
> >http://www.varlena.com/GeneralBits/49.php
> >
> >
> >Andreas
> >
> Hi Andreas,
>
> Thanks for your prompt reply. I understand why this is a sequential
> scan, I'm just a bit perturbed that it takes 4.5 seconds to execute said
> scan. The table is only 750,000 records big. What happens when this
> table 7 million records big? Will this query then take 45 seconds to
> execute?

How often do you need a 'select count(*) from big_table'?

I assume, not frequently. And if you need realy this, you can write a
trigger or read the statistics for the table.

Andreas
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Andreas Kretschmer
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