RE: Single record access really required (was RE: Views and Indexes)

["Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx>]

> From: CWilt@xxxxxxxxxxxx
> 
> Option B is where the solution lies.
> 
> How about providing some examples of standard business operations
where
> you
> feel single record access is required and we'll see if there isn't a
way
> to
> remove the requirement.

You're kidding me, right? Uh, off the top of my head - getting the GL
account number from the item class.   Requires chaining to the item
class file with the item class from the item master.

And in any business application, there are hundreds and hundreds of
instances like this.  In fact, that's the idea behind a configurable ERP
system: you read the database to determine your logic.


> Most often used one in RPG I can think of is checking a record's
existence
> to ensure data integrity.
> The need for this is eliminated with a properly defined DB that uses
> constraints properly.

This is hardly ever used.  We chain to see if the customer entered a
valid item number, and that's not going to be handled by referential
integrity.


> Another place would be a "work-with" type application where a user is
> presented with a set of items from which they chose one to edit or
> display.
> Off the top of my head, one could possibly use the same cursor that
> presents
> the set to present the single item.  This would eliminate the
performance
> differences that you've seen in your testing.  Perhaps somebody else
has a
> better idea.

How could you use the same cursor?  By doing somehow calculating the row
number and doing a FETCH -N?  It's been stated (though not proven
quantitatively) that relative fetches include I/O overhead of their own.

And that's not really the point.  The point is that you have no real
answer to this, you're just winging it.  And that's really not
acceptable in a technical discussion.

At least not to me.  I will no longer dispute "maybes" and "mights".  If
you have a solution, then write it, test it, and let us know the
results.  As of today, the day of "possible" solutions used as arguments
is over, at least for me.  From now on, the only valid solution is one
that has been tested.  And those will be posted at the IAAI website.

Joe