As an combo Oracle DBA, database designer and PL/SQL developer I have found this book to be especially valuable over many others in the area of performance tuning. It's clear and not cluttered up like official Oracle documentation, yet mines out some real jewels from a deeper than usual understanding of the Oracle engine. It's not comprehensive or systematic; the author tends to jump around covering the areas of his own expertise. This actually makes the book MORE useful. Excellent treatment of partitioning.This is not another book that simply regurgitates Oracle documentation!