Including Fast Path in a DBCTL system definition

During the DBCTL system definition process, you can specify which Fast Path application programs and resources should be included in the IMS system.

Describe Fast Path application programs as part of system definition input with:

  • The FP=Y keyword in the DFSPBxxx member of the IMS.PROCLIB data set, which causes Fast Path facilities to be included in the IMS online system and reserves certain resources for Fast Path.

    If you specify FP=N, and you attempt to use a Fast Path resource or command, the results are unpredictable.

  • The APPLCTN macro, which creates the application program definitions.

You use a system environment macro to specify Fast Path control program facilities in an IMS DBCTL environment in the same way that you use macros to specify options and buffer sizes.

Use the OTHR parameter of the IMS procedure to specify how many output threads are to be used for the asynchronous DEDB update processing.

The OTHR= parameter can have any value from 1 to 32,767. If a value is not specified, the default is 255. If 0 or a value greater than 32767 is specified, the default is 2. If a value from 1 to 32767 is specified, the specified value is used.

Use the DBFX parameter of the IMS procedure to specify the number of buffers to be set aside for DEDB updates used by sync point processing. These buffers are part of the total number given for the next parameter, DBBF. The DBBR parameter is used to specify the maximum number of buffers available to the online system for DEDB processing. Use the BSIZ parameter to specify the actual size of an individual buffer.