Re: Newbie question: ultra fast count(*)

From: Jaime Casanova <systemguards(at)gmail(dot)com>
To: Rodrigo Madera <rodrigo(dot)madera(at)gmail(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Newbie question: ultra fast count(*)
Date: 2005-11-25 19:40:06
Message-ID: c2d9e70e0511251140x5f2a6c2ah6fc81d88fcfb2213@mail.gmail.com
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On 11/25/05, Rodrigo Madera <rodrigo(dot)madera(at)gmail(dot)com> wrote:
> I have been reading all this technical talk about costs and such that
> I don't (_yet_) understand.
>
> Now I'm scared... what's the fastest way to do an equivalent of
> count(*) on a table to know how many items it has?
>
> Thanks,
> Rodrigo
>

you really *need* this?

you can do
SELECT reltuples FROM pg_class WHERE relname = 'your_table_name';

but this will give you an estimate... if you want real values you can
make a TRIGGER that maintain a counter in another table

--
regards,
Jaime Casanova
(DBA: DataBase Aniquilator ;)

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