Hi All, Software:- Oracle 9i,Oracle 10g OS - Solaris 9. We have 5 databases in our development environment. All the databases(9i) are running on Solaris 9 OS. I have given responsibility to install oracle 10g on Solaris box(development environment). Once the 10g gets install then upgrade one of the database running on the 9i to 10g. i.e. migrate all the database objects, and others stuff. I am Oracle Developer and have never involved in Administration role. I have referred few document over the net to get head-up. 1. Oracle 10g Install guide on Solaris 2. Oracle Database Upgrade Oracle 10g. After reading the document I feel I still don't have enough information on some of issue which I think it may arise. 1. approach for installing 10g 2. How to mitigation data from 9i to 10g 3. What issues does arises during installation/post installation and so on. 4. Any risk? 5. Back out strategy I would like to know 1. Install guide for Oracle on Solaris box. What precaution to take care if there is old version of database running? 2. Regarding backup and transferring data to 10g Should I just copy the data file and other files to some directory and once 10g is install copy them to 10g respective folder? 3. How would I point the old instance running on 9i database to 10g. 4. Any changes required in .profile, environment file 5. How do I make sure the upgrade of database should not affect other instance?. 6. Any link which give me further head-ups on the current project Many thanks 7. What strategy should I use to proceed further? Any suggestion are most welcome.