A PSB must contain at least one PCB. If there is any system service calls or if there is any transaction management calls present in a program, then IO PCB must be defined in PSB.
The sequence of PCBs should be as below in a program:
Entry DLITCBL Using IO PCB
- The definition of PCB is available in PSB.
- If COMPAT=YES defined in a PSB of PSBGEN, means “IO PCB” is present in the program. Say, the program is IMSDC program.
PCB TYPE=TP ==> IO PCB or Alternate PCB
PCB TYPE=DB ==> DB PCB
PCB TYPE=GSAM ==> GSAM PCB
- Once, my friend has been asked a question in an interview- How could we say a program is involved IMSDC ?
- The answer is, if “IO PCB” is present in the PCBs list, we can say that IMSDC is involved in that program.
- COMPAT=NO, means, program should contain IOPCB that is for BMP programs
- Alternate PCB ( TP PCB) also involved in BMP and MPP (IMSDC) programs.