Re: Slow query problem

Dennis Björklund <db@zigo.dhs.org>

From: Dennis Björklund <db@zigo.dhs.org>
To: Richard Huxton <dev@archonet.com>
Cc: Bradley Tate <btate@objectmastery.com>, <pgsql-performance@postgresql.org>
Date: 2004-01-09T08:57:09Z
Lists: pgsql-performance
On Fri, 9 Jan 2004, Richard Huxton wrote:

> > > select invheadref, invprodref, sum(units)
> > > from invtran
> > > group by invheadref, invprodref
> 
> > For the above query, shouldn't you have one index for both columns
> > (invheadref, invprodref). Then it should not need to sort at all to do the
> > grouping and it should all be fast.
> 
> Not sure if that would make a difference here, since the whole table is being 
> read. 

The goal was to avoid the sorting which should not be needed with that 
index (I hope). So I still think that it would help in this case.

-- 
/Dennis Björklund