History Collection of Db2 Thread 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

E3270 Thread History

OMEGAMON for Db2 thread history in the Enhanced 3270UI is the equivalent of near-term history in the Classic Interface.

Thread history (Enhanced 3270UI) and Near-term history (Classic) data is stored in VSAM data sets. Thread history in the Enhanced 3270UI is approximately equivalent to "thread-related information" in the Classic Interface's near-term history. Thread History in the Enhanced 3270UI is not aggregating the data in intermediate summaries, instead the extended filtering capabilities shouldbe used to restrict the amount of data to be displayed in the result screens.