Re: Questions about S/36 files

On 11/5/2013 12:08 PM, James H. H. Lampert wrote:

A couple of questions about S/36 files, prompted by a potential new
customer whose whole native system is apparently set up around them:

First, while I've occasionally futzed around with totally flat,
non-keyed files, and while I've used program-described mode to
circumvent level-check problems on externally-described files that
change regularly, but in a manner that's under our control, I don't have
a lot of experience with actual S-36 files. Am I correct in my
understanding that an S-36 file can be both flat and keyed at the same
time? Is there a convenient way to create a file indistinguishable from
an S-36 file on a V4 or V6 box that doesn't have any S-36 emulation
installed?

It's been decades, but my recollection is that in the native environment
we'd treat them as regular old program described files. I and O specs.
I don't recall S/36 environment files being restricted to S/36
environment only, rather that it was exactly the same to have RPG III
programs read and write S/36 files as easily as native files.

One of the very first things we did was to make DDS for the major files
and use those for external definitions. Much nicer than I and O specs.

Second, can SQL access an S-36 file? Is it difficult?

Access is as simple as select * from filename; You'll get exactly one
column - the entire record. If there are packed fields, you have to
write a function to unpack them. If there are numeric fields, you have
to CAST them appropriately. Because as far as SQL is concerned, the
table consists of one very large character column. So you'll be using
quite a lot of SUBSTR() and CAST() in your SELECT, WHERE and ORDER BY
clauses.

Make DDS for those files and your SQL life gets much easier.
--buck