Re: why the 16meg space size limit?

["Alexei Pytel" <pytel@xxxxxxxxxx>]

I don't really know what is the answer - it's not my field, but I see no
reason why it could not be done.
My guess is that it was not deemed important enough.
I honestly do not see how *USRSPC limitation hurts me as an application
designer.
It's maybe an annoying limitation, but I can live with it - and live easily
at that.

For a specific situation:
> what about the list api's like quslobj?
> Will the usrspc always have enough room for all the list entries?
I understand your concern.
I guess this is a realm of personal preferences. I for one avoid large
result sets.
I feel something inherently wasteful to retrieve so much data at once.
There are very few cases when I want *all* available data. In most cases I
would want to subset, filter, etc - to find a way to limit amount of data.

But I agree that probably APIs should start returning data in teraspace
instead of *USRSPC.
However, this is just my personal opinion.


    Alexei Pytel




                                                                                
              
                    "Steve                                                      
              
                    Richter"             To:     <MI400@midrange.com>           
              
                    <srichter@Auto       cc:                                    
              
                    Coder.com>           Subject:     Re: why the 16meg space 
size limit?     
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                    05/21/2001                                                  
              
                    06:42 PM                                                    
              
                    Please respond                                              
              
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>> can I turn the question back on you?
>> why was it so important for ibm to provide teraspace functionality?
>
>You are welcome ;-)
>Many applications want to have data structures during processing which are
>larger than 16MB (JVM, for example). With 16MB limit one has to split
these
>structures in smaller pieces, which is awkward. Teraspace solved this.
>Now if you want to store permanently vast amounts of data, you have (and
>always had!) several ways to do this.
>I've already mentioned database files and stream files.
>
>So I am back to my question - what is so special about *USRSPC object that
>you want it to be larger than 16MB ?


to answer your specific question, what about the list api's like quslobj?
Will the usrspc always have enough room for all the list entries?

It is basically a technical question re the system architecture. what are
its capabilities and limits.  what can be expected from it going into the
future. are there components of it that make it a dead end or will it be
able to evolve to meet tomorrows computing needs.

The decision to provide  teraspace functionality was a good opportunity to
expand the size limit of the space. This would have been a more seamless
solution than the teraspace.  But ibm did not do it this way.

Do you agree that expanding the space size limit would have been a better
way to provide teraspace functionality?

I learned what I know of computers by listening to ibm reasons for why the
s/38 architecture was best. single level store,  pointers with capability,
seamless migration to 64 bits, etc.  An effectively unlimited limit? ( 1
gig ) to the size of a space, is in my opinion, a logical and usefull
extension of this design concept.

I welcome the back and forth on this subject, but the question is still a a
technical one. What does it take, or what prevents the space size limit
extension.

Steve Richter




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