Mainframes, MVS, zOS and Related Languages Support Forums Help & Support Forum for and by Mainframe Users 2013-08-17T02:13:50+00:00 http://www.ibm-mainframes.com/feed.php?f=20 2013-08-17T02:13:50+00:00 2013-08-17T02:13:50+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=336&p=875#p875 <![CDATA[JCL - Job Control Language. • Re: What is the difference between FB and F and spanned reco]]>
Assume you had to buy 100 apples from the market place. If you buy just one apple every time, you'd have to make 100 trips. Transportation cost would be too high. Instead, if you bought in bunches of ten, you'd have to make just 10 trips. Also, carrying all of the 100 apples in just a single visit may be too heavy. So, there's a trade-off.

Think of the records in 1 block as apples in a bunch. You'd have to choose the optimum block-size(BLKSIZE) for you dataset.

Statistics: Posted by Quasar Chunawala — Sat Aug 17, 2013 2:13 am


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2013-08-14T10:50:41+00:00 2013-08-14T10:50:41+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=340&p=860#p860 <![CDATA[JCL - Job Control Language. • Re: What is NULLFILE and how it is different than DUMMY?]]> Reference manual for your release of z/OS, you could easily have read about DSNAME:
Quote:

12.22.2.9 Data Set Name for Dummy Data Set

NULLFILE

Specifies a dummy data set. NULLFILE has the same effect as coding the DD DUMMY parameter. NULLFILE must be coded as a single-word parameter. For instance, IBM does not support the use of NULLFILE to obtain a dummy data set for these (or other) formats:
When followed by a member name
As a qualifier in a qualified data set name
As a temporary data set name.
In other words, there is no difference between DD DSN=NULLFILE and DD DUMMY. Use which ever you prefer or your site standards require.

Statistics: Posted by Robert Sample — Wed Aug 14, 2013 10:50 am


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2013-08-14T03:42:51+00:00 2013-08-14T03:42:51+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=340&p=851#p851 <![CDATA[JCL - Job Control Language. • What is NULLFILE and how it is different than DUMMY?]]>
Can any one explain me the difference between "DD DUMMY" and "DD DSN=NULLFILE". And when should one use DUMMY and when NULLFILE?

Statistics: Posted by Anil — Wed Aug 14, 2013 3:42 am


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2013-08-13T12:06:31+00:00 2013-08-13T12:06:31+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=336&p=841#p841 <![CDATA[JCL - Job Control Language. • Re: What is the difference between FB and F and spanned reco]]>
FBS means to use standard blocks -- which means every block of the data set, except possibly the last, will be exactly the block size. The difference only comes into play when a data set is extended (DISP=MOD); with FB the new data will be written into another block (leaving possibly a short block in the data set each time the data set is extended) whereas with FBS the last block will be filled to the block size before a new block is written. Again, from a COBOL standpoint it makes no difference which you use but the system overhead will be less with FB versus FBS.

Note that VBS is completely different in meaning from VBS versus VB. VBS is variable blocked spanned and means the LRECL may be longer than the block size, and the system fills each block as full as possible.

The bottom line for a COBOL programmer is to ALWAYS use FB or VB for your data set, which if the data set is managed by SMS you won't have any control over that, anyway.

Statistics: Posted by Robert Sample — Tue Aug 13, 2013 12:06 pm


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2013-08-13T11:05:20+00:00 2013-08-13T11:05:20+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=336&p=839#p839 <![CDATA[JCL - Job Control Language. • What is the difference between FB and F and spanned records.]]>
I searched but I didn't get an answer to tell the differnce between FB/F as a COBOL programmer. When should we use which?

I looked at http://publibz.boulder.ibm.com/cgi-bin/ ... 0312141355 but the confusion remains.

For that matter what is FBS, I mean what is the practical use of it? Do we really use this format in COBOL applciations? I've just seen using FB, not even F.

Thanks for any help on this.

Statistics: Posted by Subhash Chander — Tue Aug 13, 2013 11:05 am


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2013-08-13T06:18:24+00:00 2013-08-13T06:18:24+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=320&p=836#p836 <![CDATA[JCL - Job Control Language. • Re: JCL time limit for making the Job complete by some time.]]> Statistics: Posted by Shuku — Tue Aug 13, 2013 6:18 am


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2013-08-11T06:13:30+00:00 2013-08-11T06:13:30+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=320&p=820#p820 <![CDATA[JCL - Job Control Language. • Re: JCL time limit for making the Job complete by some time.]]> Statistics: Posted by Anuj Dhawan — Sun Aug 11, 2013 6:13 am


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2013-08-07T11:16:49+00:00 2013-08-07T11:16:49+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=205&p=775#p775 <![CDATA[JCL - Job Control Language. • Re: What is the difference between elapsed time and the CPU ]]>
z/OS was designed to run with 100% CPU utilization for long periods of time. Most Unix / Windows systems were designed to run about 20% CPU utilization and can get very slow when CPU goes over 90%. One thing to remember is that compile jobs are generally considered development work and as such are less important than production work. The programmer may not agree, but if the company is running payroll or billing on the production system, few managers would be willing to make the production work take longer just so a programmer can get their compile done. And since a typical mainframe will have between 100 and 500 things going on at the same time, 24 hours a day, tradeoffs have to be made. The most common hierarchy I've seen is production online, then production batch, then test online, then test batch (which may include compiles but also they may be considered lower priority than test batch). Workload Manager (WLM) is how those priorities are enforced on a z/OS system; while WLM is not a perfect system it certainly gets as much work done as possible.

Statistics: Posted by Robert Sample — Wed Aug 07, 2013 11:16 am


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2013-08-07T04:53:17+00:00 2013-08-07T04:53:17+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=205&p=773#p773 <![CDATA[JCL - Job Control Language. • Re: What is the difference between elapsed time and the CPU ]]> Statistics: Posted by Pragya — Wed Aug 07, 2013 4:53 am


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2013-08-06T18:20:58+00:00 2013-08-06T18:20:58+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=203&p=765#p765 <![CDATA[JCL - Job Control Language. • Re: What are different operating systems in mainframes?]]> Statistics: Posted by Priya — Tue Aug 06, 2013 6:20 pm


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2013-08-06T18:13:48+00:00 2013-08-06T18:13:48+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=202&p=762#p762 <![CDATA[JCL - Job Control Language. • Re: What is the difference between restart and resubmit?]]> Statistics: Posted by Priya — Tue Aug 06, 2013 6:13 pm


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2013-08-06T18:12:18+00:00 2013-08-06T18:12:18+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=200&p=760#p760 <![CDATA[JCL - Job Control Language. • Re: GDG LRECL for different generations.]]> Statistics: Posted by Priya — Tue Aug 06, 2013 6:12 pm


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2013-08-05T09:51:25+00:00 2013-08-05T09:51:25+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=322&p=733#p733 <![CDATA[JCL - Job Control Language. • Re: Confusion about different DD names used in JCL...]]> SYSTSPRT -- usually used for output of TSO commands in batch jobs that execute TSO
SYSABOUT -- usually used for abend dump data for old (VS COBOL II) programs
ABENDAID -- used by a third-party vendor (Compuware) for its product dump
SYSUDUMP -- used by z/OS for system dumps if something abends
SYSDBOUT -- was used by the OS/VS COBOL compiler for SYMDMP output many years ago

Statistics: Posted by Robert Sample — Mon Aug 05, 2013 9:51 am


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2013-08-05T09:37:03+00:00 2013-08-05T09:37:03+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=320&p=729#p729 <![CDATA[JCL - Job Control Language. • Re: JCL time limit for making the Job complete by some time.]]> Statistics: Posted by Robert Sample — Mon Aug 05, 2013 9:37 am


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2013-08-05T09:34:37+00:00 2013-08-05T09:34:37+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=319&p=728#p728 <![CDATA[JCL - Job Control Language. • Re: SMTP parameters and IEBGENER.]]> Statistics: Posted by Robert Sample — Mon Aug 05, 2013 9:34 am


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2013-08-05T05:30:03+00:00 2013-08-05T05:30:03+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=322&p=725#p725 <![CDATA[JCL - Job Control Language. • Confusion about different DD names used in JCL...]]>
I was going through the JCLs at my system and got the to see following DD names:

Code:
SYSABOUT DD SYSOUT=A
SYSTSPRT DD SYSOUT=*
SYSPRINT DD SYSOUT=*
ABENDAID DD SYSOUT=*
SYSUDUMP DD SYSOUT=A
SYSDBOUT DD SYSOUT=A

Please let me know what are they? I don't much about them online.

Statistics: Posted by Makrand — Mon Aug 05, 2013 5:30 am


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2013-08-04T17:53:18+00:00 2013-08-04T17:53:18+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=320&p=723#p723 <![CDATA[JCL - Job Control Language. • JCL time limit for making the Job complete by some time.]]>
Is there any parameter we can specify in a JCL that can intimate zOS that the current job should be completed by this time? For example, if we give <some-parameter>=11:00 means the JOB will be completed by 11. I heard that there is a parameter supplied by JES2. However I am unable to find it. Please help.

Statistics: Posted by Shuku — Sun Aug 04, 2013 5:53 pm


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2013-08-04T17:46:38+00:00 2013-08-04T17:46:38+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=319&p=722#p722 <![CDATA[JCL - Job Control Language. • SMTP parameters and IEBGENER.]]>
I'm using SMTP parameters and IEBGENER to send the e-mail from zOS box to windows. But I think, it's not IEBGENER which sends the e-mail, it's rather the SMTP parameter which are being copied from SYSUT1 to SYSUT2, is that correct?

If yes, does that mean any utility with copy capabilities will be able to send e-mail, provided I've used correct SMTP parameters.

Statistics: Posted by Salil — Sun Aug 04, 2013 5:46 pm


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2013-08-03T15:38:22+00:00 2013-08-03T15:38:22+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=175&p=706#p706 <![CDATA[JCL - Job Control Language. • Re: What is MLDSCB?]]> Statistics: Posted by Binamra — Sat Aug 03, 2013 3:38 pm


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2013-08-03T04:10:17+00:00 2013-08-03T04:10:17+00:00 http://www.ibm-mainframes.com/viewtopic.php?t=201&p=684#p684 <![CDATA[JCL - Job Control Language. • Re: How many MAXIMUM Jobs can be submitted in a single JCL]]> Statistics: Posted by DB2 Guy — Sat Aug 03, 2013 4:10 am


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