Being that OraPub is focused on Oracle performance management, ORTA is obviously foundational. Over the years, various reports and tools focused on response time have been developed and included in the free OSM tool kit. Two key reports are a session-focused report (rtsess.sql) and an instance-focused report (rtsysx.sql). Figures 2-15, 2-16, and 2-17 are actual output from the rtsysx.sql report on a test system. Figure 2-18 is an example from the rtsess.sql script.

As I introduce these two reports here, and explore their secrets in Chapter 5, pay close attention to where the same information can be retrieved from the tools you currently use. I have discovered that nearly all Oracle diagnostic tools and products have the information you need to perform an ORTA. It's just that some products make it easier than others.

In the OSM tool kit, by default, the categories are bogus (events usually not relevant to performance analysis), ior (IO read events), iow (IO write events), and other (everything else). Part of the tool kit installation routine runs a separate script (event_type.sql) that loads a reference table containing each wait event and its associated category. When I run response time-based reports, I simply reference this table to appropriately categorize the time. If you want to add a category or change a wait event's category, just modify the event_type.sql script and rerun it. From that point on, all the OSM ORTA reports will be based on your preferred categorization scheme. This flexibility also allows you to easily categorize new wait events or fix misclassifications.