Performance Considerations for Allocate Queue Services

The relative performance of APPC/MVS callable services varies depending on the functions that the callable service performs. For example, services that call VTAM or cause the movement of data buffers involve a greater number of internal instructions.

Table 1 provides a summary of performance considerations for individual APPC/MVS allocate queue callable services. For an overview of performance considerations for APPC/MVS TP callable services, see z/OS MVS Programming: Writing Transaction Programs for APPC/MVS.

Table 1. Performance Considerations for Allocate Queue Services
APPC/MVS Service	Calls VTAM	Causes DASD I/O	Causes buffer moves	Calls RACF	Creates SMF record
Register_For_Allocates	No	See Note	No	RACROUTE REQUEST= AUTH	No
Receive_Allocate	No	No	No	No	No
Unregister_For_Allocates	No	No	No	No	No
Query_Allocate_Queue	No	No	No	No	No
Set_Allocate_Queue_Notification	No	No	No	No	No
Get_Event	No	No	No	No	No
Set_Allocate_Queue_Attributes	No	No	No	No	No
Note: Reads from the side information file if you specify a symbolic destination name.