Here's the situation: Users are angry, very angry. The Oracle Database 10g Release 2 online system residing on a single four-CPU core Linux server is taking much too long when simply querying for basic information, like a customer. But it's not just one, two, or three queries-it's the entire system. You have been assigned to diagnose the system, recommend solutions, and clearly explain the solutions, including reasonable expectations for their impact on performance.

The worksheets shown in the figures in the remainder of this chapter are all contained within a single Microsoft Excel workbook, the firefighting diagnostic template workbook.12 Only the yellow cells require input. If you enter information into a cell that isn't shaded yellow, you are typing over a formula! Data entered in one of the worksheets may be referenced in another worksheet. For example, the Oracle CPU consumption shown in the Oracle-focused worksheet (Figure 9-21) is referenced in the operating system CPU analysis worksheet (Figure 9-22). All the data-entry fields have been previously discussed. If you need more information about their source, please review the appropriate section in this book.

To summarize, the Oracle subsystem is being forced to ask for blocks outside its cache. While the operating system returns these blocks extremely fast, the number of requests results in a significant portion of the total response time. From a purely Oracle perspective, we can easily reduce the queue time by 20% by simply increasing Oracle's buffer cache.