Mainframe, MVS and zOS Discussion

Hi,

Please help me to know if we can edit a tape file? I've been asked this question in an interview. I'm not sure if I understood the question itslef. I've asked the interviewer but he repeated the same.

It is not possible to edit a tape file. Edit implies change and once written to a tape, the data CANNOT be changed (at least not without writing to a different tape).

But that idea can be applied to a DASD file too, right?

Actually, the concept applies (sort of) to a DASD file. The key difference, however, is that a DASD file can be rewritten whereas a tape cannot. The edit process is to read the data set into memory, make all the changes to the copy in memory, and when the edit session is complete then write the data set back out to DASD, replacing the previous copy. Since the last step is not possible for tapes, edit of a tape data set does not occur.

Note that rewriting data to tape is not possible because a tape may contain multiple files, and rewriting a tape could impact every file on the tape.

It does depend on what "edit" means. DITTO can. I should think Filemanager/File-Aid can as well.