[acuartero]

Suresh,

All of these are valid approaches. I don't believe that there is anything in the dbmigrate scripts for 5.5 that require 10g. As long as you don't actually start the OTM application server with a mismatched database version you shouldn't have any problems. If you actually plan on upgrading your database hardware then let me suggest a 4th approach. That is to take an export of your current 4.5 database and bring it into a 10g instance and run the migration scripts from 4.5-5.0-5.5 all in-place against the 10g database. This has the advantage of leaving your existing 9i database in place in the event that you need to rollback to 4.5 due to an unsuccessful go-live.

You would of course need to also install 4.5 , 5.0 & 5.5 along with the last SR available for each before you begin the migration. You must also run dbpatch as the last step of each version's migration scripts (the admin guide is not exactly clear about this step).

I don't know what your OS platform is but it is often easier to install the migration environments on a windows platform (a desktop or laptop is fine for migration since you won't actually start the app from here) and the fnal 5.5 environment on the target OS hardware. I would suggest that you run through the migration at least twice before the go live so you can resolve any errors (on the first run) and get accurate timings (on the second) so that you can properly schedule your activities for go-live.

Good Luck,
-Alan