ALTER DATABASE DATAFILE...ORA-03297...HELP!

Greetings:

I'm hoping someone can help me or point me in the right direction..

Here's what I'm trying to do:

I'm trying to resize a datafile in my RBS (Rollback) Tablespace from 400M to 150M. When I issue the command

ALTER DATABASE DATAFILE 'f:\mydatafile.dbf' RESIZE 150M

I get the "ORA-03297: File contains 4100 blocks of data beyond requested resize value" message. I figure that this means that there are still active transactions in the rollback file. The question is, how do I commit these transactions? I really don't care about any data that might be in the file. I've tried shutting down the database and bringing it back online again but this doesn't help. I got myself into this fix by setting autoextend ON...

How can I resize the datafile? Or how do I drop it and re-create it? Thanks for any pointers and/or references to the documentation. I've looked but it's rather muddy.

My environment: Workgroup Server 7.3.2 on NT 3.51. Received on Wed Oct 08 1997 - 00:00:00 CDT