Re: Issue with partition elimination

From: Josh Berkus <josh(at)agliodbs(dot)com>
To: pgsql-performance(at)postgresql(dot)org
Subject: Re: Issue with partition elimination
Date: 2011-04-25 18:06:47
Message-ID: 4DB5B837.2010602@agliodbs.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

On 4/21/11 6:26 PM, Paul Pierce wrote:
> What was noticed, that the only case when Postgres is actually going to execute
> the query against the right partitions is query #1.
>
> Is that by design? Second query join, will also result in 3 days(3 partitions)

Partition elimination currently can only handle constants and
expressions which are equivalent to constants. It will not filter on
Joins successfully.

This will improve somewhat in 9.1, possibly enough to fix your case.
Please test this on 9.1a5 and see how well it works, and give us feedback.

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com

In response to

Browse pgsql-performance by date

  From Date Subject
Next Message Uwe Bartels 2011-04-25 19:01:09 Re: big distinct clause vs. group by
Previous Message Віталій Тимчишин 2011-04-25 14:22:23 Re: big distinct clause vs. group by