Are you more interested in relational theory, or in implementation techniques for database systems? If the latter, the Ramakrishnan and Gehrke book (the "cow bo

Are you more interested in relational theory, or in implementation techniques for database systems? If the latter, the Ramakrishnan and Gehrke book (the "cow book") is really good: fairly broad coverage, but very well-written and precise. I haven't read the Date book.