When you run the upgrade from 3.0.1 to 3.0.1.2 the upgrade script makes some changes to the database, so I very much doubt you can point a 3.0.1.2 application to a 3.0.1 level database.

Assuming that you want to move to a different app server, I think the options you have are:
- Upgrade to 3.0.1.2 on your existing app server (thereby upgrading the DB), then do a fresh 3.0.1.2 install on your new app server
- Install 3.0.1 on your new app server and then run the upgrade process on this

One thing to be aware of is that the DB stores an ID of the RTC instance that is using it. If you connect a new install to the same DB you will need to run the repotools -resetRepoLockId command as described here.

We have one RTC Server and Oracle db, if shutdown the RTC server, does another RTC server can conect to the same Oracle db when jts/setup?

Here our RTC 3.0.1 with Oracle db has some problem, we want to install another RTC 3.0.1.2 to verify, so can I use RTC 3.0.1.2 to connect the same db?

Thanks!