program works slowly

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program works slowly

Postby leonid » Thu Feb 05, 2009 3:23 pm

I want to find place in my program (COBOL MAINFRAME) which takes long running time
How can I handle this situation?
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Re: program works slowly

Postby Bill Dennis » Thu Feb 05, 2009 7:54 pm

Long run times can be factors outside your program, such as system too busy or tape mount times. Be sure these are not the problem.

Now make sure you use large BLKSIZEs on input and output files to ensure reads/writes are most efficient.

You can trace the logic path to be sure you dont OPEN and CLOSE file repeatedly, etc.

Finally, you could put WRITE statements in at strategic points (with timestamps) to track the flow.

Bill Dennis

Disclaimer: My comments on this forum are my own and do not represent the opinions or suggestions of any other person or business entity.
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Re: program works slowly

Postby swd » Thu Feb 19, 2009 6:01 pm

Do you have a peformance monitor such as STROBE or IBM's APA ? This will pin-point exactly where the problem is. Does your program access a database - perhaps it is tablespace scanning? There could be hundreds of reasons for poor performance, so you need to eliminate possible causes.

If you don't have STROBE or APA then use DISPLAY statements with timestamps (as mentioned above)
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