Hi Niall Thanks for the reply after going through the thread its sounds like the pereceived benfit by moving to a large block size must be thoroughly tested its no gaurantee that performance will improve. I was wundering why did oracle come out with multiple block size feature considering that in my whole carrer as a DBA i have used large block size only for BLOB column storage and nothing else. Is exadata the reason for large blocksize ? regards Hrishy -- //www.freelists.org/webpage/oracle-l