The Prefetchers component displays the number of prefetchers defined for the database or partition. Prefetchers read specific index and data pages into the buffer pool, anticipating an application’s need for these pages. Because these reads are asynchronous—that is, they are performed outside of program-instruction processing—prefetchers can improve performance by reducing the time spent waiting for I/O to complete.
At each refresh, Spotlight captures the number of prefetchers defined for the database or partition. This number is based on the NUM_IOSERVERS database configuration parameter.
Click the Prefetchers component to open the Databases drilldown. This drilldown provides details about database or partition that you are monitoring. The Statistics tab on the drilldown is in immediate focus to so you can examine prefetch statistics in the database or partition.