Re: Statistics and the rule based optomizer

From: Gints Plivna <gints.plivna_at_gmail.com>
Date: 13 Sep 2006 00:01:55 -0700
Message-ID: <1158130915.703380.10970@h48g2000cwc.googlegroups.com>

> It could call a procedure that would:
> - gather stats for the segments of interest if they do not exist
> - alter the optimizer goal for the session to use the CBO
>
> (first one in, pays the price of having to wait for stats to be
> gathered)

If your table's data do not change too much very fast you can gather stats once, store them somewhere using dbms_stats.export_<xxx>_stats and then use import_<xxx>_stats to get them back. Generally it should be much faster than gathering stats each time again and again.

And yes - I've seen Thanks GOD only a person not organization, that used RBO hint wherever he put his dirty hands. Now we've got rid of all his legacy hints.

Gints Plivna
http://www.gplivna.eu Received on Wed Sep 13 2006 - 02:01:55 CDT