The CPU subsystem consists of a single four-CPU core. Based on both vmstat observations and v$osstat view data, on average, the CPUs are about 28% utilized. Over the 30-minute data collection interval, the CPU subsystem has the capacity to supply 7,203 seconds of CPU. Based on the Oracle service time analysis, Figure 9-21 shows Oracle consumed about 1,880 seconds of CPU, meaning Oracle consumed about 26% of the available CPU resources.

From a CPU subsystem perspective, it is not possible to increase scalability by somehow splitting a single Oracle server process activity onto multiple CPU cores. Our only option is to decrease total service time to use faster CPUs. Because of cost and budgetary timing issues, we do not want to entertain this option unless absolutely necessary. So at this point, we will not seek to improve performance by increasing the CPU subsystem capacity.

Based solely on the v$sysstat performance view, the IO subsystem is receiving read requests at nearly 530 MB/s. Oracle read requests (db file scattered read) are being satisfied in less than 1 ms, which indicates the Oracle blocks reside in the operating system buffer cache! While not shown in Figure 9-22, the average IO device utilization is around 2%, meaning they are idle.