IndxPgHitRatio (DB2UDB_BUFFERPOOL)

Indicates the percentage of the index reads that did not require physical disk access. This type of index read may be performed because the index data is already in the cached memory buffer pool.

This parameter can be used to help determine the correct setting for the buffpage configuration parameter. 

If RUNSTATS has been recently performed on the index, then the NLEAF column in the SYSIBM.SYSINDEXES catalog table indicates how many pages (not including non-leaf pages) the index requires.

The BUFFERPOOL DB2 Monitor Switch must be set ON to make this parameter active and collect data.

This parameter uses the delta calculations.

Recommendation

If the ratio value is too low, increasing the number of buffer pool pages may improve performance.

Parameter value calculation

Note: During first collection cycle, the parameter would not populate a value since there is no value for the previous pool index physical and logical reads. From next collection cycle, parameter will compute and populate the value. Also, the IndxPgHitRatio parameter will go into an offline state during first collection cycle, however, parameter will return to online state from the next collection cycle.

Default parameter attributes