Measuring DDF activity

If you measure a DB2® DDF address space with the DB2+ extractor turned on, Application Performance Analyzer captures the remote SQL activity detected in the address space. The data is reported in the following reports: F02, F10, F11, F12, F15, F16, F17, F18 and F19. The only other report available for a DDF measurement is S01 Measurement Profile.

For DDF measurements only, Application Performance Analyzer records the enclave CPU time, zIIP time, and zIIP on CP time for each observed SQL call.

There are some limitations when reporting on a DDF address space:
  1. The SQL calls observed will not correlate one-for-one with those issued by the application at the requester site. Some calls will not be observed because they are not sent to the DDF address space.
  2. Multiple SQL calls can be issued by DB2 when processing a particular SQL call. For example, an OPEN call could result in FETCH and CLOSE calls being issued by the DDF address space. These calls will have the same statement number as the OPEN call.
  3. When a CALL statement results in invoking a stored procedure in the same DB2 subsystem, the stored procedure calls can also be observed in the DDF address space.
  4. Some dynamic SQL statements can be shown as static. This is because the DDF address space is treating them as though they are static.
  5. The SQL function of remote SQL calls display as the actual SQL function, however because they are remote:
    • The SQL text might not be accurate.
    • Issuing an EXPLAIN request against a SQL statement with a type of Remote SQL can result in an error at the server rather than being caught in the TSO session of the user.
  6. Some SQL calls have a statement type of Remote SQL instead of the expected SQL type. For example, INSERT and DELETE calls are observed as Remote SQL. As a consequence:
  7. A CALL statement might not always have SQL text available.
  8. A DESCRIBE statement does not have any SQL text available.
Note:
  1. If you want to select a DDF address space from a list when setting up the measurement, enter *DIST in the Job Name pattern field, unless your organization has changed the DDF address space naming standard. In that case, contact your DB2 system administrator to obtain the name of the DDF address space in your organization.
  2. If you want to limit the scope of a DDF measurement, you may filter the measurement for specific Correlation Id, End User Id and/or Workstation Id in Panel 5 of the NEW dialog.
  3. The Number of Samples specified for a DDF measurement is not used because each DDF call is intercepted rather than sampled. The number of samples will always be converted to approximately one per second.
Parent topic: Overview of DB2 data extractor