Figure 2-12. This is the code to retrieve information about a specific block. This is very useful when linking Oracle's analysis with the application and the operating system. This code is the core of the OSM objfb.sql script.

If we perform a few more samples, we will get a good idea of the objects the session is waiting for and also where the objects reside. This information provides a very important 3-circle analysis link to the application and also to the operating system.

In this example, from an application perspective, we should expect to find SQL that is requesting blocks from the orders table. Look for that SQL. You will find it. It must be there, because if it were not run, it would be impossible for a session to be waiting for a block in the orders table. From an operating system perspective, if the average wait time is significant, we should expect the device where the associated database file resides to be very busy, or the path from the server process to the database file to be hindered in some way. This example demonstrates that with only limited but very specific information, you can make a pinpoint diagnosis.