The previous example was based on a two-CPU core system experiencing a raging CPU bottleneck. Here, we will walk through the same process, but with a larger system experiencing a classic multiblock IO read bottleneck.

This example is based on a real Oracle Database 10g Release 2 system with four CPU cores. The performance data is based on a standard 60-minute interval AWR report. We will complete each of the five steps outlined in the previous sections, resulting in the response-time graph.

The database server bottleneck is the IO subsystem. Simply put, Oracle's IO read requirements have exceeded the IO subsystem's read capacity. We will expect our response-time graph to reflect the general queue time increase of an IO bottleneck, which has a continual and steady increase in queue time until the elbow of the curve is reached, and then response time skyrockets.