Importance of a Performance History

To build up a performance history and profile of your system, take frequent regular snapshots of resource-utilization information:

• Chart the CPU utilization and paging-out rate for each coserver, and the I/O transfer rates for the disks on your system to identify peak-use levels, peak-use intervals, and heavily loaded coserver components.
• Monitor fragment use to determine whether your fragmentation scheme is correct.
• Monitor other resource use as appropriate for your database server configuration and the applications that run on it.

If you have history information on hand, you can begin to track down the cause of problems as soon as users report slow response or inadequate throughput. If history information is not available, you must start tracking performance after a problem arises, and you cannot tell when and how the problem began. Trying to identify problems after the fact significantly delays resolution of a performance problem.

Choose tools from those described in the following sections, and create jobs that build up a history of disk, memory, I/O, and other database server resource use. To help you decide which tools to use to create a performance history, the output of each tool is described briefly.