[no subject]

<snip>

Is there native GDS [or GDG as I remember them] (generation dataset)
support on the iSeries? If not, can it be *simulated* without much
effort?

</snip>

 

Answer:  No, there is not GDS support on the System i.  It can be
simulated by using multiple member files, but that is not an approach
that is consistent with cross-functional design and SQL standards.  

 

The biggest advantage to a GDS is its ability to reference a prior
version of the dataset by changing the reference JCL, and when it gets
to the end of the number of generations, it just "automagically" rolls
over to generation 1 and starts over.  A solution that might duplicate
most of that functionality could be built in CL (Particularly at V5R4)
as a preprocessor to any program that would use the GDS but it would
take some contemplation on how to set it up.  Truly an interesting
project.  

 

The trick would be to set up some commands so that the override-database
statements would be handled properly to point at the generation that is
requested.  The other aspect of it would be to always clear the data
from the target file upon open, another aspect of GDG.  Again possible,
but I would ask the fundamental question, why not just set up a properly
keyed database table and use SQL from the start, since in any
incarnation of a GDS substitute that is about what I would do.  

 

 

Jim Oberholtzer

Systems Architect

CDW

The Right Technology. Right Away.(tm)