C. J. Date is an independent author, lecturer, researcher, and consultant specializing in relational database systems, a field he helped pioneer. Among other projects, he was involved in technical planning for the IBM products SQL/DS and DB2. He is best known for his books, in particular, An Introduction to Database Systems (7th edition, Addison-Wesley, 2000), the standard text in the field, which has sold well over half a million copies worldwide. Mr. Date is widely acknowledged for his ability to explain complex technical material in a clear and understandable fashion.