Locking Activity reports and traces

The locking activity provides various levels of detail about concurrency control within Db2 in the form of reports, traces, and a file data set.

It shows information about:

  • Db2 transaction locks, which are locks on table spaces, tables, pages, or rows. DB2 transaction locks are used primarily to control access by SQL statements.
  • DB2 drain locks and DB2 claims, which control access by DB2 utilities and commands.
  • Global locks in a data sharing environment.
  • DB2 lock avoidance techniques and related locking data, such as page latch waits.

Locking activity reports (also referred to as locking reports) summarize all user activity related to lock suspensions and lockouts. The reported information is grouped and ordered by OMEGAMON® XE for DB2 PE identifiers, which you can specify:

  • A Suspension report is a summary of lock suspensions across the reporting interval for a unique combination of selected OMEGAMON XE for DB2 PE identifiers. The report also shows the number of occurrences and elapsed times, the causes, and the reasons for resuming processing.
  • A Lockout report is a summary of users and resources involved in timeouts and deadlocks. For each event, the user holding the resource and the users waiting for the resource are identified, along with the number of occurrences and other statistics.
  • A Lock Detail report contains complete information about lock-related events.

Locking activity traces (also referred to as locking traces) provide information about lock events as they occur. Locking traces differ in the level of detail as follows:

  • A Detail trace contains complete information about lock-related events in a Db2 system, or a group of Db2 systems in a data sharing environment. It shows all IMS/VS Internal Resource Lock Manager (IRLM) requests, IRLM suspensions, timeouts, deadlocks, claim and drain activities, lock-avoidance occurrences, and inter-DB2 requests in a data sharing environment.
  • A Deadlock trace shows every occurrence of a deadlock.
  • A Lockout trace shows each timeout and deadlock.
  • A Suspension trace shows every lock suspension.
  • A Timeout trace shows each timeout.