Re: SQL question: something analogous to a multi-format logical . . .

James H. H. Lampert wrote:

Combining what Vern offered with what Elvis offered, and testing
it on our V5 box, I found that I could set up a UNION VIEW.

But is there any way to index it, so that when opened through
native RLA (in this case, from C), it's sequenced according to
first the "user number" field, then Vern's library tag field?

In other words, the same effect as if I INSERTed the UNIONed
SELECT into a receiver [ed: temporary\intermediate] PF that
was keyed on those two fields (which is another concept under
consideration, but would have its costs).

Should be possible to use the SQL to define the set, and then to use the OPNQRYF KEYFLD() against that SQL VIEW database *FILE [as the named QRYFILE()] to define the [order\collation for the] keyed RLA interface through a shared open data path.

Also under consideration is a non-SQL possibility, the use of a
trigger to slave a composite PF to all of the individual instance
enrollment files. (And God knows I have experience doing insanely
complex things in triggers, including slaving one file to
another, and somehow getting away with it!)

Multiple copies of the data.? Ugh. Of course it could still be SQL, as SQL trigger(s) :-)

James H. H. Lampert wrote:

Is there something that can be done in SQL, that would
effectively make a bunch of instances of the same file,
in several different libraries, look like a single file?

Case in point: a user enrollment file, associated with
an instance of an application.

Regards, Chuck