>Creating a view that captures this fact: >Select * > from table > Where closed_dt >=3D open_dt > and open_dt >=3D closed_dt - 10 > >Now accessing the view: > >Select * > from view >Where closed_dt =3D 15 As I just wrote in the previous reply, in my opinion, the structures = used to support end-user queries should be designed exactly for that. = This means, that such workaround with views should simply not be used. >Oracle is able to substitue closed_dt with 5 only where closed_dt >appears by itself >So the where looks like: > >Where open_dt <=3D 15 > and closed_dt =3D 15 > and open_dt >=3D closed_dt - 10 > >Optimizer can't take advantage of : open_dt >=3D closed_dt - 10 Notice that if you don't use the view, Oracle should be able to perform = the correct pruning. -- //www.freelists.org/webpage/oracle-l