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pankaj1002
New User
Joined: 30 Jul 2012 Posts: 18 Location: India
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Hi Friends,
I am a new learner of IMS DB. At one point I got stuck in understanding that, for e.g., lets say if my cobol program needs to access multiple databases, then how does the CBLTDLI call understands that which database it needs to access to find the segment information.
I know, For multiple database we have to provide as many PCB masks at Linkage section and Procedure division.
My confusion is because we dont provide any DBD information when we call CBLTDLI.
CALL 'CBLTDLI' USING WS-GU-FUNC (Function)
CDB-PCB (system information after each call)
CDB-IO (IO-Area)
WS-RAP01-SSA
WS-RACTL-SSA |
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PeterHolland
Global Moderator
Joined: 27 Oct 2009 Posts: 2481 Location: Netherlands, Amstelveen
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Ed Goodman
Active Member
Joined: 08 Jun 2011 Posts: 556 Location: USA
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The PSB entries line up with the Entry statement (DLITCBL) items.
That second parm in the IMS call is one of those items in the Entry statement. When you specify one of those PCBs, you are pointing to a database, simply by picking the correct PCB.
If you use the AIBTDLI call instead of CBLTDLI, you can actually specify the name of PCB. However, you have to define the names in the PSB when you generate it. |
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Anuj Dhawan
Superior Member
Joined: 22 Apr 2006 Posts: 6250 Location: Mumbai, India
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pankaj1002 wrote: |
My confusion is because we dont provide any DBD information when we call CBLTDLI. |
At program level PSB/PCB are the "interfaces". DBD is 'Physical' Database Definition; in one sense, program does not need to know about it -- why do you think it should be provided?
Possibly, a vague correlation can be -- in a simple Batch-COBOL program, you don't provide the physical attributes of a DSN and the DD Name for the file is enough to get your program working. Co-relate it with IMS terminologies and it might just help... .
Hope this helps. |
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