Re: Question - dissimilar Plans in 'identical' environments

From: Matthias Hoys <idmwarpzone_NOSPAM__at_yahoo.com>
Date: Thu, 21 Jul 2005 00:59:25 +0200
Message-ID: <42ded74e$0$18245$ba620e4c@news.skynet.be>

"BD" <bobby_dread_at_hotmail.com> wrote in message news:1121898827.155041.319020_at_f14g2000cwb.googlegroups.com...
> Additional:
>
> I am running dbms_stats.gather_db_stats in my test environment, but the
> stats are being put into a table, not the dictionary. It's been
> suggested that the new stats may be the factor, but I thought that in
> order for the cbo stats to be used, the stats had to be imported into
> the dictionary, and the cbo turned on in the init file.
>
> Bleargh.
>

What do you mean with "the stats are being put into a table" ? What's the use of this ?
If the optimizer mode is CHOOSE, and you are joining tables with stats to tables without stats, the RBO is used. If there are stats for all the tables, CBO will be used. Is your init.ora file the same in prod as in test ? There are a lot of init.ora parameters which influence index usage.

Matthias Received on Wed Jul 20 2005 - 17:59:25 CDT