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"Delete Option. In order to keep the number of records in the overflow area
to a minimum, and to eliminate unnecessary records, an existing record may
be marked for deletion. This is done by moving the figurative constant
HIGH-VALUE into the first character position of the record. The record is not
physically deleted unless it is forced off its prime track by the insertion
of a new record (see "Using the WRITE Statement" in "Accessing an Indexed
File Randomly"), or if the file is reorganized. Records marked for deletion may
be replaced (using BISAM) by new records containing equivalent keys.
Execution of the READ statement in QISAM does not make available a record
marked for deletion, whether the record has, been physically deleted or
'not."
Joe
On Sun, Sep 22, 2019 at 8:18 PM Vince Coen [email protected] [H390-MVS] <
[email protected]> wrote:
>
>
> Well I have been programming in Cobol since around 1964/5 from IBM
> 1401,7094, ICL1900's,IBM360s and yes a lot more after the 60's and I do
> not recall using anything other than DELETE having move the record key in..
>
> Now I cannot say it was the same for the 1401/7094 as I do not have a
> manual to hand but 360 and 1900 yes.
>
> The idea of use high-values into the key I have never seen but there
> again my memory may be playing tricks and I am only 72.
>
> Vince
>
> On 20/09/2019 19:51, [email protected] [H390-MVS] wrote:
> > Many thanks, that's a very useful post (and very nostalgic!).
> >
> > I played around with some of the examples, and got them working with
> > little trouble. The main difference, as far as I can see, between your
> > manual and the COBOL MVT compiler that we have on the turnkey system,
> > is in the way that ISAM records are deleted.
> >
> > Your manual uses a DELETE statement, that I've never seen before. I
> > did it the more traditional way, by putting HIGH-VALUE in the
> > DELETE-KEY field and then doing a REWRITE. Worked fine, it's the way I
> > remember from about 1967 or thereabouts.I guess things have moved on
> > since then.
>
>
>