If you have a histogram then the optimizer should correctly recognize the historic outliers. How did you create the histogram, what does dba_histograms contain for that column and what are the problem queries like? BTW I see a Y3K problem looming. Alfonso León wrote: > Hello everyone: > > Now there > are about 5 million records and half of them are historic so there are > 2.5 million records with 31-dec-2999 and it is confusing the > optimizer. > -- Regards Wolfgang Breitling Centrex Consulting Corporation www.centrexcc.com -- //www.freelists.org/webpage/oracle-l