System monitor switches self-describing data stream

After you update or view the switch settings of the current system monitor with the db2MonitorSwitches API, the API returns the switch settings as a self-describing data stream. Self-describing data includes data attributes such as element names and sizes.

Figure 1 shows the structure of the switch list information that may be returned for a partitioned database environment.
  1. Descriptive names are used for the identifiers in the examples and tables. These names are prefixed by SQLM_ELM_ in the actual data stream. For example, db_event would appear as SQLM_ELM_DB_EVENT in the event monitor output. Types are prefixed with SQLM_TYPE_ in the actual data stream. For example, headers appear as SQLM_TYPE_HEADER in the data stream.
  2. For global switch requests the partition order of the returned information can be different in each switch request. In this case, a partition id is included in the data stream.
Figure 1. Switch List Monitor Data Stream
Switch list monitor data stream
  1. Each logical data group begins with a header that indicates its size and name. This size does not include the volume of data taken up by the header itself.
  2. Size in the collected header returns the total size of all monitor switch lists for all partitions.
  3. The size element in switch list header indicates the size of switch data for that partition.
  4. Switch information is self-describing.
  5. For a non-partitioned database, the switch settings for the stand alone partition are returned. That is, only one switch list is returned.