Re: Concatenation of files

[Al Mac <macwheel99@xxxxxxxxxxx>]

I believe the rules vary with the method of software used to get at the data.

There are some rules associated with "classic relational data base" which 
many programming standards adhere to, then there is legacy data that many 
of us need to support.

In my scenario, I first used DDS to create a join-logical in which I used 
keys from the two different files.  I got fatal error messages.  I found a 
different way to get at the report my people wanted (list receivables 
sequenced by customer name, a datum that is not in the receivables file, 
but customer # is), by creating a logical which CONTAINED data from another 
physical file, then ACCESSED in sequence from the combined files.

With OPNQRYF and OVRDBF you can DEFINE one file in the compile, but 
actually input a DIFFERENT file at execution time.

With OPNQRYF the input can in fact be the concatenation of several files, 
in which the rules what to include, do not actually include all the data of 
the various files.

Sometimes I use SQL to get stuff, but I have had a real bear of a time 
getting at compound SQL conditions out of multi-format files.  Generally, 
when I run into a hassle with something, I find another way to get what the 
people want, then do my continuing education as time permits.
:
> Hi:
>
> This doesn't sound right. We have several multi-format logicals built on
> physical files with radically different formats. Certain utility setups,
> such as DBU in multi-record mode, don't work with such files, but that is
> not a problem for the most part.
>
> The original message didn't mention indexes. However, record order is
> probably implicit in the question.
>
> I *believe* we are running programs that depend on the order of records in
> multi-format logicals. This suggests that these logicals are indeed
> indexed (in some way) on values from different files. I would be
> interested in the rules if this is not true. It might help solve some
> long-term nagging problems.
>
> Darrell
>
> Darrell A. Martin  -  754-2187
> Manager, Computer Operations
> dmartin@xxxxxxxxxxxxx