Figure 4-12. An excerpt from a production Oracle system's 10-minute duration AWR report showing operating system statistics. This output is based on the v$osstat view.

* CPU consumed can be taken directly from Figure 4-12 BUSY_TIME of 17,250 hundredth seconds (hs), which is very important, since we must maintain a constant unit of time in our calculations. This means that over the 10-minute period, all processes on the database server consumed 17,250 hs, or 172.50 seconds.

* CPU available is the time interval multiplied by the number of CPU cores. In Figure 4-12, the time interval is 10 minutes, which is 600 seconds (10 _ 60). The number of CPU cores is four, so the CPU power available is 2,400 seconds (600s _ 4 cores, or 4 cores _ 10 minutes _ 60 seconds / 1 minute).