What to read after Mastering Oracle SQL and SQL*Plus?

It is a true honor to be asked to write an introduction to a book by Lex de Haan. I just hope I can give Lex the credit he deserves for his friendship, knowledge, enthusiasm, carpentry . . . and sheer energy in the many years we’ve been doing things in the Oracle world. Lex spent 14 years in Oracle, starting as an instructor in Oracle Netherlands, becoming initiator and coordinator of Oracle’s excellent Technical Seminar business, and finally ending up in Oracle’s Curriculum Development division as a manager for a bunch of very excellent course developers. He is never afraid to start up something new, to enter new and untried waters... a personal trait he shares with about 0. 00001% of the global population. Then, finally, Lex started up for himself, and, of course, the company name had to reflect his twisted, funny way of thinking: Natural Join. Who else can get away with it, looking sto- faced and with just the slightest twinkle in his eyes, if you look really carefully? Since then Lex, as always, hasn’t looked back but has worked nonstop as instructor all over Europe and the Middle East, and as writer. The book in front of you is, in fact, an update of a book he wrote many moons ago, and which has served as a textbook in various Dutch schools.