15.1 Tuning Oracle CPU Usage

CPU usage can be best assessed at peak times and thus peak CPU workload times. What are peak workloads? This depends entirely on your application. An OLTP application is generally active and available 24 h a day, 365 days a year. There may be peak times and quiet times for OLTP databases but any very large highly active OLTP database generally passes batch operation work onto a data warehouse database, wherever possible. DSS-type databases tend to be a mixture of OLTP, client-server, and data warehouse type functionality. Therefore, some databases may have peak workloads for different types of activity at different times of the day. It is quite possible that client-server or OLTP-type service is provided during the day and batch operations are processed at night. The point to be made is this. Do not waste your time looking for something wrong with CPU usage when the CPU is idle. Wait until the CPU is really busy and then try to figure out what is overloading it, if anything. The CPU could simply be busy because busy is what it is meant to be!

So what do we do about tuning CPU usage? Well we cannot actually tune...