Tuning of SQL code is generally cheaper than changing the data model.
Physical and configuration tuning involves a search for bottlenecks that
often points to SQL code or data model issues. Building an appropriate
data model and writing properly performing SQL code can give 100%+
performance improvement. Physical and configuration tuning often gives
at most a 25% performance increase. Gavin Powell shows that the central
theme of Oracle10gR2 Performance Tuning is four-fold: denormalize data
models to fit applications; tune SQL code according to both the data
model and the application in relation to scalability; create a
well-proportioned physical architecture at the time of initial Oracle
installation; and most important, mix skill sets to obtain the best
results.

* Fully updated for version 10gR2 and provides all necessary transition
material from version 9i
* Includes all three aspects of Oracle database tuning: data model
tuning, SQL & PL/SQL code tuning, physical plus configuration tuning
* Contains experienced guidance and real-world examples using large
datasets Emphasizes development as opposed to operating system
perspective
http://rapidshare.com/files/45315203...n.Sep.2006.rar
or
http://www.megaupload.com/?d=K8QDO7X5