Guys , Thanks a ton for all your valuable replies . I was surprised to see no one using rrdtool . I thought it is widely used by oracle community . Would like to know if anyone is using RRDTOOL ?!!! Hi Tanel , Many thanks for that excel . Let me try that too . - prem - Explore your hobbies and interests. Go to http://in.promos.yahoo.com/groups/ -- //www.freelists.org/webpage/oracle-l