SOFTWARE DEVELOPMENT

Developing Time-Oriented Database Applications in SQL
by
Richard Snodgrass

A great book that covers creating temporally aware database designs and supporting applications. Not for the faint of heart, but it is still one of the best books on the topic I have seen.
SQL for Smarties
by Joe Celko


This is the first book I turn to if I am trying to figure out a SQL problem...
SQL Puzzles and Answers
by Joe Celko


... this is the second.
What not How
by
C.J. Date

Anything Date has to say is worthy of reading, but I especially like this book. It's short, poignant, and right on.