Lex de Haan (11 August 1954 – 1 February 2006)[1] was an independent author, lecturer, researcher, and consultant, specializing in relational database technology.
Between 1988 and 1990 Lex developed his own courseware as an independent contractor in "De Haan Consultancy", advised organizations about education needs, and delivered classes.
Lex taught seminars and courses as Natural Join B.V. (data server internals, Oracle Database 10g new features, and SQL) in Belgium, France, Denmark, Slovakia, Sweden, Turkey, United Kingdom, Ireland, Saudi Arabia, and Bahrain.
Lex de Haan also delivered some well-received presentations during the Hotsos Symposium in Dallas (Texas) and the UKOUG Conference in Birmingham.
Lex de Haan also started writing a new book, together with Toon Koppelaars, with the exciting tentative title "Applied Mathematics for Database Professionals" to appear mid-2006.