Hi, When ETL process runs its good option to keep the tables in nologging option but you shuod make sure the backup does not happen at this time we faced this issue when we refreshed the prod database to one of the Test databases where we found block corruption,Changing the backup timing solved the issue, this suggestion might not be relevent to the topic its just a suggestion/ Thanks Achi On 12/11/07, GovindanK <gkatteri@xxxxxxxxx> wrote: > > Did you check with v$sess_io and v$sql to find out which statement is > doing the max io? > > Govindan > > > -- > //www.freelists.org/webpage/oracle-l > > >