----- Original Message -----
From: "Fabrice Scemama" <fabrices@ximmo.ftd.fr>
To: <pgsql-general@hub.org>
Sent: Thursday, April 06, 2000 4:03 PM
Subject: [GENERAL] Accelerating subqueries
> Hi fellow PostgreSQL users.
>
> Here's a query:
>
> DELETE FROM Annonces WHERE Id_Ag IN
> (
> SELECT Id FROM Installs
> WHERE Si_Compte_Actif = 'f'
> );
>
DELETE FROM Annonces WHERE EXISTS (SELECT Id FROM Installs WHERE
Si_Compte_Actif ='f' AND Installs.Id=Annonces.Id_Ag);
ought to be a lot faster if you have indices on all concerned fields.
But this should be faster still;
DELETE FROM Annonces WHERE Annonces.Id_Ag=Installs.Id AND
Installs.Si_Compte_Actif='f';
Yours,
Moray
