Sandra, Since I don't see where anybody has replied to your question, I'll at least give you some ideas. For Oracle, Tom Kyte is great at explaining things in simple terms. Take a look at his Expert Oracle Database Architecture. In more general terms, usually the search term is "data modeling". You might start with the Wikipedia article, and Google for lots of good web sites out there. You don't mention your personal background, but it is good to start with an understanding of the Normal Forms (1st. NF, 2nd NF, etc.) Hope this helps, Dennis Williams -- //www.freelists.org/webpage/oracle-l