Fast Path dependent region parameters in DCCTL or DB/DC

The positional parameters (PARM=) for a Fast Path dependent region in DCCTL or DB/DC environments are described in this topic.

Note: The DCCTL environment does not support Fast Path databases. It does support Fast Path processing and transactions.

The PARM= positional parameters for Fast Path dependent region's EXEC statements are shown in Table 1.

Table 1. Fast Path dependent region parameters for DCCTL and DB/DC
Category	Parameter
Database and PSB	NBA OBA MBR PSB
Data communications	none
Region control and performance	IFP OPT PRLD PREINIT STIMER DIRCA CPUTIME DBLDL SSM ALTID PARDLI
Recovery and restart	TLIM SOD
Security options	IMSID

The EXEC statement's first positional parameter, IFP, causes this region to be active for Fast Path processing only. The MBR parameter specifies the name of the message-driven application program.

Two database-related parameters, NBA and OBA, control how many of the total Fast Path buffers this region can appropriate for its use. If you are using the Fast Path 64-bit buffer manager, the combined values of NBA and OBA make up the maximum number of buffers reserved for storage. If you are not using the Fast Path 64-bit buffer manager, DBBF controls the maximum number of buffers reserved for storage.

The NBA parameter specifies how many buffers are reserved for DEDB and MSDB processing by this region. 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 9 999. 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.

The OBA parameter specifies how many buffers are requested from the control region as overflow when the normal allotment is used up. 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.

Both the NBA and OBA parameters are generated with a 0 (zero) value so that you must respecify the individual values.