DSNB820I AVERAGE RESIDENCY TIME FOR DIRECTORY ENTRIES = d1 FOR DATA ENTRIES = d2

If the DISPLAY GROUPBUFFERPOOL command specifies the GDETAIL option, the output includes statistics on the residency times for items in the group buffer pool.

Note: Message DSNB820I returns 0 values unless Db2 13 runs in the following software and hardware environment:

• z/OS® 2.4 or later, with PTFs required for cache residency time metrics applied.
• IBM® z16® or later processors.
• Coupling facility at CF Level 25 or higher. For more information, see CFLEVEL and operating system level coexistence.

This message always returns weighted-average values, regardless of whether the DISPLAY GROUPBUFFERPOOL command specifies GDETAIL(INTERVAL) for GDETAIL(*). The values are 0 if the group buffer pool has not yet been reclaimed.

DSNB820I – AVERAGE RESIDENCY TIME 
              FOR DIRECTORY ENTRIES                   = directory-entry-reside-time 
              FOR DATA ENTRIES                        = data-area-reside-time 

directory-entry-reside-time

The weighted average in microseconds of the elapsed time that a directory entry resides in a group buffer pool storage class before it is reclaimed.

data-area-reside-time

The weighted average in microseconds of the elapsed time that a data area resides in a group buffer pool before it is reclaimed.