Fast Path parameters in BMP and CCTL regions in DBCTL
The Fast Path positional parameters (PARM1= and PARM2=) for batch message processing and CCTL regions in a DBCTL environment are described in this topic.
The PARM1= and PARM2= positional parameters for a BMP region's EXEC statements are shown below. The Fast Path parameters in the DRA startup table that the CCTL must use when it connects to a DBCTL environment are also shown.
| Category | Parameter | Purpose |
|---|---|---|
| Database and PSB | NBA | Specifies the number of database buffers |
| OBA | Specifies the number of overflow buffers | |
| MBR | Specifies name of message-driven program | |
| PSB | Specifies PSB name | |
| CCTL | CNBA | Total number of buffers for this CCTL |
| FPB | Number of database buffers each thread uses (from the CNBA total) | |
| FPOB | Number of overflow buffers each thread might need |
Two database-related parameters, NBA and OBA, control how many of the total Fast Path buffers this region can appropriate for its use.
The NBA or CNBA parameter specifies how many buffers are reserved for DEDB processing. This normal allotment is obtained at region startup and must be available from the total number specified for the control region. Specify a number from 1 to 9999. If you are not using the Fast Path 64-bit buffer manager, coordinate the value across all regions that are to be concurrently active and specify the total on the DBBF parameter. If too few buffers are available from the DBBF total, the dependent region abends. If you are using the Fast Path 64-bit buffer manager, IMS controls the expansion of the buffer pools, and the DBBF parameter is not valid.
After a CCTL is connected, each CCTL thread request for Fast Path PSBs receives an allotment of buffers.
The OBA or FPOB parameter specifies how many buffers are requested from the control region as overflow when the normal allotment (NBA, FPB) is depleted. The control region page fixes the largest number of overflow buffers specified for all active BMPs and CCTL threads. If you are not using the Fast Path 64-bit buffer manager, the buffers are made available to only one program at a time. If you are using the Fast Path 64-bit buffer manager, multiple dependent regions can extend into the overflow buffers concurrently. Choose a value from 1 to 9999 that is a suitable common value for all regions.
Both the NBA and OBA parameters are generated with a 0 (zero) value so that you must respecify the individual values.
Related reading: For more information about DEDB buffer considerations in a DBCTL environment, see IMS Version 15 Database Administration.