Buffer pool statistics - fields (ISPF)
This topic describes the statistics that are displayed on the Buffer Pool Statistics panel.
- Buffer Pool Hit Ratio (%)
- The hit ratio for buffer pools.
- Calculation
- Hit Ratio = (Get Page Requests - Synchronous Pages Read - Async Pages Read) / Get Page
Requests * 100%Note: This formula differs from the formula that OMEGAMON Batch Reporter uses to calculate Buffer Pool Hit Ratio, so a different calculation result is expected.
- Get Page Requests
- The number of getpage requests. This includes conditional, unconditional, successful, and unsuccessful requests. The GETPAGE information for a program reported on the activity summary might not add up to the sum of object detail GETPAGEs of that program due to the trade-off between optimizing the collector for efficiency and increasing the level of detail in some statistics.
- Buffer Pages Updated
- The number of buffer pages updated.
- Synchronous Pages Read
- The number of synchronous read I/O for the object.
- Synchronous Pages Written
- The number of synchronous write I/O for the object.
- Sequential Prefetch Requests
- The number of SEQ PREFETCH requested for the object.
- List Prefetch Requests
- The number of LIST PREFETCH requests for the object.
- Dynamic Prefetch Requests
- The number of DYNAMIC PREFETCH requested for the object.
- Asynch Pages Read
- The number of asynchronous pages read by prefetch.
- zHyperlink Cache Hits
- The number of read with disk cache hits.
- zHyperlink READ I/O
- The number of SyncIO read with zHyperlink.
- zHyperlink Read Elapse Time
- The elapsed time for successful zHyperlink reads.