Lisa,
I don't think you can find this information. If oracle patch has been Installed but you did not applied the patch instructions, I guess there is no way to tell. If these is difference between major version of datafile and software installed e.g. If the datafiles are 8.1.6 version and suppose you use oracle 9i software to mount oracle 8i database, I am sure , you will get error.

Sanjay

Originally posted by DBA_Lisa
I don't think ANY v$ views can tell the version about the database. Here is my reasoning:

1. start an instance in NOMOUNT.
2. Now you can check v$version, v$instance

However, the datafiles have not been accessed. The v$ views are actually derived from the Oracle Kernal. It's about the version number of installed Oracle product. It's NOT for the database's version number.

So, doesn anybody there can answer this question?