If you can't lay hands on Oracle database software and related tools, it's very difficult to become proficient in this complex, challenging but also rewarding DBMS environment. So if you don't work in or around an environment where Oracle is available to you, you may want to rethink your goals. DBA work in general is a decent place to be. (Number 10 on the CertCities 10 hottest certs for 2003 list is the MCDBA, shared with a Citrix Admin cert; no Oracle certs on this list either.) But given your Microsoft background you may be better served by going after MCDBA certification instead.
HTH. Please feel free to e-mail me directly if you have further questions or concerns.
This was first published in April 2003