Re: Query take 101 minutes, help, please - Mailing list pgsql-performance

From Steinar H. Gunderson
Subject Re: Query take 101 minutes, help, please
Date
Msg-id 20050907165754.GA12319@uio.no
Whole thread Raw
In response to Query take 101 minutes, help, please  (Christian Compagnon <ccompagnon@gmail.com>)
Responses Re: Query take 101 minutes, help, please  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-performance
On Wed, Sep 07, 2005 at 12:22:27PM -0400, Christian Compagnon wrote:
> I'm a newbie in postgresql, I've installed it on a Windows XP machine
> ( I can't use linux, it's a company machine ), I'm courious why this
> query takes so long

It sounds like you've set work_mem too low; increasing it might help. Also
try rewriting your query to

  SELECT "Rut Cliente"
  FROM "Internet_Abril"
  WHERE
    "Rut Cliente" NOT IN ( SELECT "Rut Cliente" FROM "Internet_Enero" )
    AND "Rut Cliente" NOT IN ( SELECT "Rut Cliente" FROM "Internet_Febrero" )
    AND "Rut Cliente" NOT IN ( SELECT "Rut Cliente" FROM "Internet_Marzo" )

(I'm not sure how optimized UNION inside an IN/NOT IN is.)

/* Steinar */
--
Homepage: http://www.sesse.net/

pgsql-performance by date:

Previous
From: Christian Compagnon
Date:
Subject: Query take 101 minutes, help, please
Next
From: Meetesh Karia
Date:
Subject: Re: Query take 101 minutes, help, please