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What is a PCB Mask?
Posted: Wed Jan 07, 2015 4:43 pm
by LalitaForums
Hi,
Can you please explian me what is a PCB mask? I have read through the manuals but I do not get it. Can there be a simple explnation about it?
Is not it just same as PCB?
Re: What is a PCB Mask?
Posted: Thu Jan 08, 2015 12:11 pm
by Anuj Dhawan
Hi LalitaForums,
No - it is not same as PCB. After all "mask" must have been added for some purpose!
Every (COBOL-IMS) program will have its own PSB known as 'Program Specification Block'. The PSB used by a program will contain one or more PCBs. For a program to communicate to the database, program
talks to PSB ( as PSBs are stored externally to the application program) and in turn,
talks to the database. In doing so, program needs a communication with PCBs in the PSB - which is done using PCB Masks.
The PCB mask holds IMS interface details like this:
Code: Select all
Database Name Char 8
Hierarchical Level Char 2
DLI Status Code Char 2
Processing Options Char 4
Reserved for DL/1 Binary 4
Segment Name Feedback Char 8
Feedback Key Length Binary 4
Number of Sensitive Binary 4
Segments
Key Feedback Area Char n
Hope this helps.