Oracle Performance Tuning for 10gR2 (2nd ed.)

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