RE: 250 libraries. a solution?

[Jim Damato <jdamato@xxxxxxxxxxxxxxxxx>]

In your scenario legacy programs would use the old variable.  The old
variable used to contain the user library list.  Now it would only contain
the first 25 entries of the user library list.  The program wouldn't bomb,
but you wouldn't be aware when it became wrong.  The program is going to
retrieve what it thinks is the library list and act on that value.

Go out onto your own system right now and find an example of a program that
retrieves the library list using RTVJOBA.  Pretend that you now have forty
entries in your library list.  Also pretend that IBM implemented the 250
library enhancement "the right way."  Run through the code and figure out
what would happen if the RTVJOBA command successfully retrieved the "short
library list".  Yeah, the program wouldn't bomb on that statement, but I'll
bet the results aren't pretty.

Two typical uses of RTVJOBA for the library list are:

1)  To see if a library is in the list and, if not, try to add it.
2)  To save a copy of the library list, change the list, run a process, and
restore the original list.

Once you go over 26 libraries you're hosed no matter what.  In scenario 1
the program may not find the library it is looking for, then the program
might bomb on an ADDLIBLE statement.  In scenario 2 the program would not
restore the full original library list, and could bomb the next time the job
looks for an unqualified object.

If it were me, I'd rather have the program bomb.  Then I could realize that
my program is not able to retrieve the full library list, and that I'd have
to fix it.  If IBM were hell bent on preventing the RTVJOBA statements from
generating the error they'd likely be pushing the problem further down the
line.

I guess customers are going to actually have to read the V5R1 release notes
and act on them.

No matter how IBM implemented the increase to 250 libraries it was going to
create code problems.  Every proposed better implementation could have a
negative impact on legacy code, if the customer exceeds 25 libraries.  I
could take any one of the suggestions of alternate parameters, system
values, system data areas, mode parameters in job descriptions and find a
way to describe them as "breaking users' code".

IBM finally enlarged the user library list.  Hooray!  It's about time.
Customers now have two choices:

1)  Adjust their code to compensate.
2)  Be careful to stay within the old 25 library limit.

If you don't have your source anymore I guess you're stuck with only one
choice.

-Jim

James Damato
Manager - Technical Administration
Dollar General Corporation
<mailto:jdamato@dollargeneral.com>


-----Original Message-----
From: Jim W [mailto:jimw2001@hotmail.com]
Sent: Wednesday, May 30, 2001 10:02 AM
To: MIDRANGE-L@midrange.com
Subject: Re: 250 libraries. a solution?



It seems to me that the obvious (and easiest for everyone) solution would be

for IBM to leave the variable for the first 25 libraries the same so there 
would be no effect on old programs, then add another return variable for 
libs 26-250.  If they want to make it even easier, there could be an 
additional (3rd) variable that would contain all 250.

How hard would that be?

Jim Whalen

----Original Message Follows----
From: "Steve Richter" <srichter@AutoCoder.com>
Reply-To: MIDRANGE-L@midrange.com
To: <MIDRANGE-L@midrange.com>
Subject: 250 libraries. a solution?
Date: Tue, 29 May 2001 18:38:15 -0400

A possible solution to the 250 libraries crashes the v5r1 rtvjoba cmd 
problem:

The cpp of RtvJoba is QCLRTVJA.

<SNIP>




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