Essentially, Oracle has extended the instrumentation approach into service time-that is, CPU consumption. While the time model is not perfect, and there are still only two service time classifications, it's a significant leap forward and sets the stage for some truly amazing self-aware, self-tuning, and self-adjusting features. So this is a very big deal, and it works wonderfully.

In keeping with Oracle naming conventions, there are two time model views: v$sess_time_model and v$sys_time_model. Two key CPU statistics are used to classify CPU service time:

As I'll demonstrate, an active Oracle process updates the time model performance views about every 6 seconds. All time is in milliseconds, so be sure when converting to seconds to divide by six zeros-that is, 1,000,000.