Date: Fri, 8 Jul 2005 10:55:50 -0500
From: Bruno Wolff III <bruno@wolff.to>
To: PFC <lists@boutiquenumerique.com>
Cc: Kenneth Gonsalves <lawgon@thenilgiris.com>,
	Ramakrishnan Muralidharan <ramakrishnanm@pervasive-postgres.com>,
	pgsql-sql@postgresql.org
Subject: Re: two sums in one query
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	PFC <lists@boutiquenumerique.com>,
	Kenneth Gonsalves <lawgon@thenilgiris.com>,
	Ramakrishnan Muralidharan <ramakrishnanm@pervasive-postgres.com>,
	pgsql-sql@postgresql.org
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On Fri, Jul 08, 2005 at 16:49:44 +0200,
  PFC <lists@boutiquenumerique.com> wrote:
> 
> >>SELECT (SELECT sum(amount) FROM table WHERE debit=X) AS debit, (SELECT
> >>sum(amount) FROM table WHERE credit=x) AS credit;
> >
> >If most of the records are credits or debits you don't want to do this.
> >A single sequential scan through the table will be the best plan.
> 
> 	I thought that debit = source account # and credit = dest account #, 
> 	and  there are a lot of different account...

You aren't likely to see a significant speed up in that case either.