We have a 9.2.0.6 DB with more than 5 terra.Right now we have maintennce every week for 5 Hours.During this hours we normally do changes to schemas(such as rebuilding indexes adding columns to some application tables etc).Now our customer wants to reduce the down time to 0 for this kind of changes.Let me know what is the best practice to make the changes to schemas without affecting the onlines and 0 down time.

Some of you guys might have the db 24/7.How you do the changes without affecting onlines???.


We tried redef package/rebuild online but all this take more time to sync the database.

We do have standby's for the production db's.

Thanks