Based in my few experience in histograms I decided to run this command EXEC DBMS_STATS.GATHER_SCHEMA_STATS( OWNNAME=>'DAZ', ESTIMATE_PERCENT=>100 METHOD_OPT=>'FOR ALL COLUMNS SIZE SKEWONLY'); with the only goal of giving more information to CBO- I didn't tested if this really gives a improvement, but I read something in some place that says it does. I don't remember where. Any comment about the previous command? ---------------------------------------------------------------- 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 -----------------------------------------------------------------