From: | Bruce Momjian <bruce(at)momjian(dot)us> |
---|---|
To: | Adriano Lange <alange0001(at)gmail(dot)com> |
Cc: | Tobias Zahn <tobias-zahn(at)arcor(dot)de>, Robert Haas <robertmhaas(at)gmail(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: GEQO: ERX |
Date: | 2009-05-28 02:04:25 |
Message-ID: | 200905280204.n4S24PJ19673@momjian.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Is this a TODO item?
---------------------------------------------------------------------------
Adriano Lange wrote:
> Hi
>
> Tobias Zahn escreveu:
> > Hello Adriano,
> > thank you very much for posting your patch. I think it will help to make
> > further work easier, too. I hope you don't mind when I ask you some
> > questions.
> >
> > When you said that this new approach is worse or equal than GEQO, did
> > you refer to performance or to the quality of results?
>
> Not exactly this approach, but the implemented (and not configured)
> algorithm was worse than GEQO in a little test made. I just used a
> sequence of 8 executions of a query with 18 relations for each
> algorithm. The costs generated by GEQO was little better than 2PO, in
> average and standard deviation. But 8 executions and 1 query don't prove
> anything. I want to make some further tests, but this little difference
> seems good for me.
>
> > Why do you think that compressed annealing might be the better approach?
>
> I don't think if compressed annealing is better or not. I don't read
> about it yet.
>
> However, an optimizer can be better in a context but worse in another.
>
> Regards,
> Adriano
>
> --
> Sent via pgsql-hackers mailing list (pgsql-hackers(at)postgresql(dot)org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-hackers
--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ If your life is a hard drive, Christ can be your backup. +
From | Date | Subject | |
---|---|---|---|
Next Message | Aidan Van Dyk | 2009-05-28 02:09:09 | Re: PostgreSQL Developer meeting minutes up |
Previous Message | Josh Berkus | 2009-05-28 02:02:59 | Re: search_path vs extensions |