I wonder what kind of optimizer bug it is. I tried various hints, even RULE !, to no avail. However, adding rownum to the innermost sql produces the expected result: SQL> l 1 select distinct deptno from ( select rownum, deptno, job, 2* min(sal) from scott.emp group by rownum, deptno, job) SQL> / DEPTNO ---------- 10 20 30 3 rows selected. SQL> l 1 select * from ( select distinct deptno from ( select rownum, deptno, job, 2* min(sal) from scott.emp group by rownum, deptno, job) where deptno = 20 ) SQL> / DEPTNO ---------- 20 1 row selected. That seems to indicate some unnesting related error. However, using no_unnest hints does not change the behaviour. At 03:55 PM 5/16/2004, you wrote: >On 9205 database, load $OH/admin/utlsampl.sql > >run following query ... and observe ... > >set feedback on >prompt Step 1 >select deptno, job, min(sal) from scott.emp group by deptno, job >/ >prompt Step 2 >select distinct deptno from ( select deptno, job, min(sal) from >scott.emp group by deptno, job ) where deptno = 20 >/ >prompt Step 3 >select * from ( select distinct deptno from ( select deptno, job, >min(sal) from scott.emp group by deptno, job ) where deptno = 20 ) >/ regards Wolfgang Breitling Centrex Consulting Corporation 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 -----------------------------------------------------------------