practical databasing - starter info

Hi
Having studied database theory long back in college, and never having used it practically ever, I now want to give a take on it. Installed Oracle 8i server, opened sqlplus - created tables and tried some queries - it worked. there is more here, some terminology new to me. (like tns listener, user tables, system tables, relationships/associations, views, triggers, stored procedures, data-sources, etc). Should I really need to learn these to be able to use a database. Any good online tutorial on these things?

Now I want to do it from java. I hear two terms - jdbc and jdo. am new to both. somebody says jdo is today's hot stuff. Can I skip entirely learning jdbc?

Good and/or brief tutorials on these are welcome.

thanks
csk

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-csk

If your clone kills you, is that suicide ?