That, of course, is the crucial piece. The index must contain a "not null" column or else Oracle can not guarantee that every row will be indexed and that therefore the count of indexed entries will be equal to the count of rows. At 06:20 PM 1/29/2004, you wrote: >17:19:19 rsysdevdb.radisys.com - jkstill@dv01 SQL> alter table >count_test modify( row_number not null) >17:19:19 rsysdevdb.radisys.com - jkstill@dv01 SQL> create index ct_idx_1 >on count_test(row_number); Wolfgang Breitling Oracle7, 8, 8i, 9i OCP DBA Centrex Consulting Corporation http://www.centrexcc.com ---------------------------------------------------------------- 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 -----------------------------------------------------------------