Locate the segment without knowing the PCB's

shamsundar_mk · New User Joined: 18 May 2007 Posts: 30 Location: CHENNAI

Hi all,

I am new to IMS, i can't understand that while we are writing the programs we did not mention the PCB's, we are just giving the PSB's. so how the program is going to locate the segment without knowing the PCB's.

Devzee · Posted: Fri Jun 15, 2007 6:45 pm

is the DLI calls in sub routine?

Bitneuker · Posted: Fri Jun 15, 2007 6:50 pm

Why don't you post the piece of program you're confused about? Also post the PSB please. Does any of your modules contain the PCB-DLIcall?

Also remember that one doesn't specify PSB's in a program but the PCB's defined in the PSB. Don't confuse PSB with PCB's.

Sandy Zimmer · Posted: Fri Jun 15, 2007 7:01 pm

Hi!

The PSB is written in Assembler and gen'd into the IMS system. It contains each database that your program will need and the processing options you will be using.

PCB's are in the linkage section of your program. This must be in the same sequence as defined in your PSB. When issuing IMS calls, the PCB for that particular database contains all of the info from that return call. After each IMS call, you must look at what your return code is. There are other fields that are extremely helpful in determing POSITION and key values returned, segment level, etc. NEVER-EVER-EVER move anything into your PCB - it belongs to IMS.

Your entry statement must contain all of the PCB's in your linkage section - in that EXACT order.

avina · New User Joined: 04 Dec 2007 Posts: 16 Location: Kolkata

Hi,

PCBs are the main communication block ofr your application pgm to communicate with the IMS db. The Linkage section will have the PCBs in the same order as in PSB, else your program will not work. Then include the Root and the other segments copybooks,if any, in the the working storage before you make the ENTRY 'DLITCBL' USING the PCBs in the Procedure Section.