Re: Large querie with several EXISTS which will be often runned

From: Josh Berkus <josh(at)agliodbs(dot)com>
To: "Bruno BAGUETTE" <pgsql-ml(at)baguette(dot)net>, <pgsql-performance(at)postgresql(dot)org>
Subject: Re: Large querie with several EXISTS which will be often runned
Date: 2003-06-27 15:41:40
Message-ID: 200306270841.40634.josh@agliodbs.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

Bruno,

> I will have to manage more or less 10.000 products with more or less 2-3
> options by products and more or less 40 options-groups.
>
> Do you think that this query will be hard for PostgreSQL (currently
> 7.2.1 but I will migrate to 7.3.2 when going in production environment)
> ?
> How can I improve that query to be faster ?

Collapse the inner EXISTS into a straight join in the outer EXISTS. Since you
are merely checking for existence, there is no reason for the subquery
nesting.

--
Josh Berkus
Aglio Database Solutions
San Francisco

In response to

Responses

Browse pgsql-performance by date

  From Date Subject
Next Message Patrick Hatcher 2003-06-27 19:09:50 Memory question
Previous Message Bruno BAGUETTE 2003-06-27 14:32:21 Large querie with several EXISTS which will be often runned