It is quite interesting, that Oracle require to gather statistics on DD within Apps environment: ========================== Metalink Note 216550.1 ?Interoperability Notes Oracle Applications Release 11i with Oracle9i Release 2 (9.2.0)? step 18 Gather statistics for SYS schema ========================== . However doesn?t recommend in general: ========================== Metalink Note 245051.1 ?Gathering Data Dictionary Statistics? Gathering statistics on the Data Dictionary in Oracle9i is a supported activity. In the majority of cases, gathering Data Dictionary statistics should not be necessary (and would not normally be recommended) since the dictionary has been optimized to cater for most common database setups. ========================== . :) Jurijs 9268222 ============================================ http://otn.oracle.com/ocm/jvelikanovs.html Tanel Põder <tanel.poder.003@xxxxxxx> Sent by: oracle-l-bounce@xxxxxxxxxxxxx 20.07.2004 17:50 Please respond to oracle-l To: <oracle-l@xxxxxxxxxxxxx> cc: Subject: Re: No stats, why the heck is CBO running??? > Yet a simple query to find the "next extext that wont fit" is always using the CBO??? > > This SQL queries DBA_TABLES and DBA_FREE_SPACE. There are NO hints in the SQL. > > What the heck? But there are hints in DBA_FREE_SPACE: SQL> select text from dba_views where view_name = 'DBA_FREE_SPACE'; TEXT ---------------------------------------------------------------------------- ---- select ts.name, fi.file#, f.block#, f.length * ts.blocksize, f.length, f.file# from sys.ts$ ts, sys.fet$ f, sys.file$ fi where ts.ts# = f.ts# and f.ts# = fi.ts# and f.file# = fi.relfile# and ts.bitmapped = 0 union all select /*+ ordered use_nl(f) use_nl(fi) */ ts.name, fi.file#, f.ktfbfebno, f.ktfbfeblks * ts.blocksize, f.ktfbfeblks, f.ktfbfefno from sys.ts$ ts, sys.x$ktfbfe f, sys.file$ fi where ts.ts# = f.ktfbfetsn and f.ktfbfetsn = fi.ts# and f.ktfbfefno = fi.relfile# and ts.bitmapped <> 0 and ts.online$ in (1,4) and ts.contents$ = 0 These kind of issues are one of the reasons why one should avoid putting hints inside views... Now, when you join several unanalyzed tables with one analyzed one, CBO will be used by default and default statistics will be used for unanalyzed tables (or dynamic sampling depending on optimizer_dynamic_sampling parameter). Tanel. ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html ----------------------------------------------------------------- ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------