This chapter discusses the tuning process based on the Oracle performance views.This chapter contains the following sections: The remainder of this chapter discusses instance tuning using the Oracle dynamic performance views.This simplification is particularly noticeable in reducing the effort to keep systems updated.For Oracle Solaris 10 and earlier, it was not uncommon to spend time dealing with patch dependency issues.JRockit was made free and publicly available in May 2011.Many JRE class files distributed with JRockit exactly replicate those distributed with Hot Spot.However, Oracle recommends using the Automatic Workload Repository and Automatic Database Diagnostic Monitor for statistics gathering, monitoring, and tuning due to the extended feature list.See "Overview of the Automatic Workload Repository" and "Automatic Database Diagnostic Monitor".
This information includes such things as disk response times and CPU response times.These statistics are used by the query optimizer to choose the best execution plan for each SQL statement. Because the objects in a database can be constantly changing, statistics must be regularly updated so that they accurately describe these database objects.Optimizer statistics include the following: The optimizer statistics are stored in the data dictionary. Statistics are maintained automatically by Oracle or you can maintain the optimizer statistics manually using the package also provides procedures for managing statistics. You can export statistics from one system and import those statistics into another system.An administrator had no idea of the amount of work that would be required for applying a single patch, i.e.resolving situations where one patch had been superseded by another or become dependent on another patch being applied.