Data manager page set data records
Use this section as a reference for the format of the data manager page set data records
The format of the data manager page set statistics record is described in assembler macro thlqual.SCSQMACS(CSQDQIS1).
The page set usage information helps to facilitate better management of local queues within a queue manager by recording information such as page set input-output rates and highest usage.
The data provides the same basic page set information as output by the MQSC DISPLAY USAGE TYPE(PAGESET) command, or the PCF Inquire Usage (MQCMD_INQUIRE_USAGE) command.
For example:
- The total pages
- The current used pages
- Unused persistent and nonpersistent pages
- Expansion method
- Number of extends
- Number of stripes
The data also provides some performance indicators, together with other performance information. For example:
- How many times deferred write, immediate write, and read page I/O requests happened during the SMF interval,
- The number of pages moved, elapsed time and number of read and write operations.
- How many pages written in checkpoints.
- Has expansion occurred during the SMF interval?
- How many times the page set became full.
- An indication of where new space is being allocated within the page set.
From the information displayed, we should be able to understand the general status of each page set, and consider whether we need to retune the system.
Parent topic: Interpreting IBM MQ for z/OS performance statistics
Related reference