Chapter 8. Performance Tuning

Performance tuning is as much an art as a science when it comes to Oracle database systems. In the past, different performance tuning methodologies were used in a random fashion without a valid scientific method. For example, Oracle DBAs would use methods for tuning the buffer cache hit ratios based on experience rather than tested formulae. Using so called silver bullets produced a haphazard solution at best, without a true understanding of the root cause of a performance issue. With the advent of the Oracle Wait Interface (OWI), many of these old and inaccurate techniques have finally been laid to the dustbins of false myths. The first step in the performance tuning of Oracle RAC environments is to tune the database itself, as you would for a non-clustered Oracle database environment. By assessing basics such as database instance tuning, as well as efficient SQL query tuning, most of your performance issues can be addressed before moving on to the more challenging...