Scenario 1: Determining the maximum number of open files

Scenario 1 determines the maximum number of open files.

The MAXFILOP parameter specifies the maximum number of database files that any single database agent can have open at the same time. If opening a file might cause this value to be exceeded, DB2® closes a file already in use by this agent. If the value of MAXFILOP is too small, DB2 encounters the overhead of opening and closing files so that the system does not exceed this limit. The overhead can become excessive and cause performance degradation. SQL response time can slow considerably. You can monitor the opening and closing of files by using the Database workspace, Database Summary workspace, and Database I/O Activity workspace. In the Buffer Pool Activity area, you can determine the value of the Files Closed attribute.

The Files Closed attribute can help you determine the best value for the MAXFILOP configuration parameter. If the number of files being closed exceeds the norm in your environment, consider increasing the value of MAXFILOP parameter until the opening and closing reaches an acceptable level.