Mainframe, MVS and zOS Discussion

START only works with DYNAMIC or RANDOM access mode -- you cannot use it with sequential.  Conversely, READ NEXT won't work for RANDOM access mode.

Do NOT post your completely irrelevant question on the back of someone's topic.  Start your own topic instead.  And your question is so broad as to be meaningless.  Does the COBOL program update a sequential data set? a VSAM data set? a DB2 table? all of them?

It depends upon what you mean by "bad data" -- since what you consider bad may be perfectly valid.  For example, consider the hex characters X'0097995D'.  If they are treated as packed decimal, the value is -97995.  If they are treated as binary, the value is 9,935,197.  If they are treate...

Generally, VSAM data sets (like sequential data sets) will be read sequentially from the first record to the last.  You can use direct reads instead of sequential reads to skip around in the data set.   CICS does allow you to read in a reverse fashion by allowing EXEC CICS READPREV but this only app...

I try not to give absolute answers because there are so many different ways to configure a mainframe.  A GDG, for example, may be SMS-managed or non-SMS-managed and how they behave is slightly different.

Companies that use mainframes are regularly surveyed and report that they see the need to use mainframes into the 2030's and 2040's and sometimes even longer.  IBM's latest mainframes are very focused on cloud computing and newer technologies.  Your question frames mainframes as either/or with cloud...

From https://www.howtouselinux.com/post/ssh-known_hosts-file:  "The ssh known_hosts file is a file that stores the public key of all of the servers that you have connected using ssh." and "In the context of computer networking, known_hosts is a file used by SSH (Secure Shell) clients ...

"When you say roller off that means "they are deleted? ". If yes, what happens to the data in them?"  Depending upon how your site is set up, they may be immediately deleted or they may be in ROLLED-OFF status for some period of time.  Eventually, they will be deleted.  And just ...

COBOL programs, when compiled, are not using variable names.  They are using offset and length instead.  So when making changes to a copy book, AS LONG AS THE OFFSET AND LENGTH do not change, the copy book does not need to be recompiled into programs.  However, any changes to offsets or lengths requ...

It depends upon the changes. Assuming the copy book has some filler, and assuming that the filler is at the end of the copy book, then you can change it with little impact. If the copy book has no filler, or if the filler is not at the end, then every program using that copy book will need to be rec...

If you click on the Post Reply button (not the Quick Reply), you will see a row of icons. The fifth and sixth icons from the left are for lists.

Try this:One note: if you change the limit and decrease it, then generations will be rolled off so the GDG matches the new limit.

Why do you not want to use any utilities or condition codes?

And why would you think you need to? Just edit the JCL, change DD3 to point to fileX, and submit it.

Use IDCAMS to REPRO from the tape file to print. The last record printed will be the one you want. If your site has SAS, it's pretty easy to code up a SAS program to print just the last record (but you didn't ask for just the last record, you just said you want to print it so printing the entire dat...

After the DFSort step, add a step using IEFBR14 that has the data set (not file) coded DISP=(OLD,DELETE) or DISP=(MOD,DELETE).

I think the question is more what YOU want to do and how you want to be categorized. IT executives repeatedly say in surveys that their company use of mainframes will continue for 10 ... 15 ... 20 years or more so moving away from mainframes may, at some point, limit your career. A December 2022 art...

Googling sort with vsam returns about 174,000 hits and will tell you what you want to know.

Without modifying the JCL in some way, it is not possible to selectively execute job steps. This question comes up pretty often -- interviewers seem to like using it -- but the answer doesn't change. It may be possible to use a job scheduler to set up the steps to execute, but that would depend upon...

There is no relationship between job names and file (data set) names. A single job may reference hundreds or thousands of data sets and inversely a single data set can be used by thousands of jobs. So there is not a TSO command to do what you want.