Oracle query / view performing very slow.

Question

Hello,
I had created a view in my application for example
CREATE OR REPLACE VIEW EmpTransfer
( EMPID,EMPNAME,EMPMANAGER,EMPDOB,EMPTRANSFER)
AS
SELECT EMPID,EMPNAME,EMPMANAGER,EMPDOB,EMPTRANSFER
FROM EMP ;
After couple of months if we changed a columnname in the table EMP and added a new column.
We changed column name EMPTRANSFER to OldEMPTRANSFER and added a new column as NEWEMPTRANSFER.
The indexes were recreated on OldEMPTRANSFER and new index is creatd on NEWEMPTRANSFER column.
the view is again recreated.
CREATE OR REPLACE VIEW EmpTransfer
( EMPID,EMPNAME,EMPMANAGER,EMPDOB,OldEMPTRANSFER,NEWEMPTRANSFER )
AS
SELECT EMPID,EMPNAME,EMPMANAGER,EMPDOB,OldEMPTRANSFER ,NEWEMPTRANSFER
FROM EMP ;
This view is working as expected but some times this view is working very slow.
The performance of this view is randomly slow.
Is it possible that column name change will cause slowness...?

Answer 1

What's the explain plans for both before and after the column change? It could possibly be running slow the first time because of a hard parse due to the query change, which will remain until it's in the shared_pool.
Edited by: DaleyB on 07-Oct-2009 04:53