Near Term History Collector

The Near Term History Collector captures and stores recent Db2 instrumentation data and to enable the review of thread performance data.

Classic Near Term History Collector

The data that is captured by the Classic Near Term History Collector includes statistics and accounting records written by Db2. The Classic Near Term History Collector might also collect certain performance data at the thread level such as dynamic SQL or sorting, locking, and scanning information.

Many events are too short-lived to be viewed in real time. Near Term History collection identifies threads that have experienced problems in the past few hours. These threads can then be examined in more detail to help identify the cause of the problem.

Some of the types of thread problems that can be identified in this way are:

  • Excessive CPU or elapsed time
  • Threads that have had timeouts or deadlocks
  • Threads committing too infrequently
  • Threads that have aborted
  • Threads with excessive lock waiting time
  • Threads with excessive Db2 wait time for I/O