This book is the revised and extended version of a Pfr.D. dissertation submitted
to the Department of Electrical Engineering and Computer Sciences, University of
California at Berkeley. Many of the ideas presented in this book have their roots in
discussions with Eugene Wong, my mentor and thesis advisor. I would like to thank
Gene for being most supportive throughout the ups and downs of my years in gradu-
ate school. Our cooperation could not have been better.
Thanks to Mike Stonebraker for his advice and helpful criticism. Mike helped
me get started at this university, and it was he who convinced me to stay in Berkeley
beyond my Master's degree. Thanks also to the members of my thesis committee,
Carlo Sequin and Dorit Hochbaum, for reading the various versions of my thesis and
for providing me with several suggestions for improvement.
My years at Berkeley would not have been nearly as great without the loyal
support of my best friends here and abroad: Grace Fan, Markus Flik, Michael Mast,
Pictro Perona, Hans, Helga & Stefan Sprung, Magan Vikramsingh, Arnold Wassner
and Andreas Wcigcnd. I would also like to thank my colleagues in the INGRES
group, at the International Computer Science Institute, and elsewhere: Jeff Bilmcs,
Peter Deussen, Joachim Dicderich, Marc Fanty, Jerry Feldman, Eric Hanson, Yannis
Ioannidis, Ron Kay, Werner Kiessling, Wolfgang Was, Kurt Mehlhom, Hanan
Samet, Timos Sellis, Wolfgang Wahlstcr and many others who always had time for
discussions and who gave me valuable suggestions, not only concerning my
scientific work.
I would like to acknowledge the German National Scholarship Foundation,
which first encouraged me to go abroad and supported me throughout the first three
years at Berkeley with two scholarships. The National Science Foundation and the
Army Research Office provided funding under grant numbers DMC-8300463 and
ARO-DAAG 29-85-K-0223. The IBM corporation supported me during the final
phase of my doctoral studies through their IBM Graduate Fellowship program, and
the International Computer Science Institute provided me with the opportunity of
spending eight more months at Berkeley as a postdoctoral fellow.
