RE: Access Key for a Sub File ?

[Joel Fritz <JFritz@xxxxxxxxxxxxxxxx>]

> IMHO, to mirror an ordered subfile key into an ordered array just adds
> another layer of programmed synchronization and a potential for
> failure.  The value is already in the subfile (in order), why take up
> more resource to replicate?
> 
> Let's see, 9,999 potential elements per subfile times value 
> length times
> number of users or managing dynamic user space when about 50 lines of
> code can do the job? I don't think so.
> 

I think there are some situations where shadowing a subfile in arrays or
data structures is a good idea.  You can support rudimentary undo that way.
If you use RPGIV array overlays or more complex techniques in RPG Classic,
you can allow users to sort the subfile in a disgusting variety of ways.
There's the situation where you want to move forward and backward in time
where the subfile holds one screen time period's worth of data.

Personally, I don't find it that hard to code.  Once you write the indexing
routines you don't have to think about it too much. If you design the
program carefully, it's unlikely that anyone doing maintenance will ever
have to pay attention to the lower level indexing stuff.  Remember, this is
only my opinion and should no way be construed to be good programming
practice or the product of a healthy mind.

My real question is:  OK, you've got a lot of records in your subfile,
enough to warrent a binary search (a cool idea, I hadn't thought of doing it
in a subfile).  Is there a significant performance difference between doing
this in an array and a subfile?  
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