Mainframe prerequisites

The mainframe system on which the Db2® Query Monitor monitoring agent, Query Monitor subsystem, ISPF client, and CAE agent run must meet these requirements.

  • IBM® z/OS® Version 2.4
  • IBM Tools Customizer for z/OS 01.01.00 (PTF UI80211)
  • Db2 12 and later, until end of support for the given Db2 version
  • IBM SMP/E for z/OS V3.6 (5655-G44) at the latest maintenance level.
  • IBM Db2 Data Access Common Collector for z/OS V1.1 (5639-OLC) or later
  • ISPF Version 4 and later
  • z/OS support for Unicode. The installation of z/OS support for Unicode with SMP/E is described in z/OS Planning for Installation (GA22-7504).
  • Db2 Query Monitor can be run with Extended Address Volumes (EAV) 223GB volumes without restrictions.
  • Hardware support of zSeries-6 to support the zEC12 instructions is required for Db2 AI feature.

Calculating Db2 Query Monitor CPU usage

Db2 Query Monitor CPU overhead is not reflected in the Db2 Query Monitor started tasks. Overhead for Db2 Query Monitor started tasks is normally insignificant and consistent. Db2 Query Monitor use intercepts into the Db2 address space to monitor and collect the SQL performance metrics. This method is efficient, but because it takes place in the Db2 address space, you must look in the Db2 application CPU to visualize any CPU overhead caused by Db2 Query Monitor collection of SQL performance metrics.

To calculate the CPU cost of running Db2 Query Monitor:

  1. Collect Db2 accounting and statistics traces and report the Db2 class 2 CPU time. Collect the trace both when Db2 Query Monitor is active and when it is inactive.
  2. Compare the results of the trace when Db2 Query Monitor is active to the trace when Db2 Query Monitor is not active .

Storage for the Db2 Query Monitor collector address space

Db2 Query Monitor is designed to use 64-bit storage. The use of 24-bit storage is minimal outside the z/OS required control blocks (the majority of which are system-controlled). 31-bit storage is used more than 24-bit storage but is still limited to programs and transitory buffers.

When the z/OS REGION parameter specifies a value less than 16 MB, the specified value represents the amount of memory below the 16-megabyte line with 32 megabytes of storage available between the 16-megabyte line and the 2-gigabyte bar.

Because Db2 Query Monitor primarily uses 64-bit storage, the amount of 24-bit storage is minimal, and 32 MB is enough for 31-bit storage. Hence, 512 MB is sufficient for running the CQM collector.