When processing these files, the COBOL Code is processing only the first 4 files(files above dummy statement).
In the IBM manual it states that -
Quote:
The system treats data sets concatenated to a DUMMY data set as dummy data sets in that I/O operations are bypassed. However, the system performs disposition processing and allocates devices and storage for any concatenated data sets.
It says I/O opeartions are bypassed. Now the question, when they say I/O operations are bypassed do they mean nothing will be read after dummy statement. I am having difficulty in understanding that part of statement. As per the program behaviour I/O operations have been performed till first dummy statement is found and after that nothing was read. So the I/O operations will be bypassed from DD Dummy statement onwards. Please correct me, if i am wrong.
Joined: 10 May 2007 Posts: 2455 Location: Hampshire, UK
Quote:
The system treats data sets concatenated to a DUMMY data set as dummy data sets in that I/O operations are bypassed
You obviously do not understand the text in bold in that you do not seem to realise that the text 'I/O....bypassed' relates to the dummy datasets and its concatenated datasets. Also, the fact that the program managed to only read the files before the first DUMMY should have answered your question.
Joined: 06 Jun 2008 Posts: 8696 Location: Dubuque, Iowa, USA
From section 4.5.1 of the JCL User's Guide manual:
Quote:
Requests to Read or Write a Dummy Data Set
When the program asks to read a dummy data set, an end-of-data-set exit is taken immediately. When the program writes to the dummy data set, the request is recognized but no data is transmitted. VSAM supports dummy data sets for both read and write processing. BSAM and QSAM support requests to write to a dummy data set. If any other access method is used, the job is terminated.
Joined: 22 Apr 2006 Posts: 6250 Location: Mumbai, India
saurabh39 wrote:
It says I/O opeartions are bypassed. Now the question, when they say I/O operations are bypassed do they mean nothing will be read after dummy statement. I am having difficulty in understanding that part of statement. As per the program behaviour I/O operations have been performed till first dummy statement is found and after that nothing was read. So the I/O operations will be bypassed from DD Dummy statement onwards. Please correct me, if i am wrong.
They are bypassed once they get to DUMMY, before that it is not.
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