Assuming equal number of I/Os to files in a remote region, which method is likely to present more CPU overhead: DPL to common I/O module resident in the region with the files or function shipping using standard MRO?
In performance terms, I don't think that there will be too much in it either way. However, I would prefer the function shipping route as that's more of an architected CICS-y way of doing things rather than you having to write the program yourself.
Naturally, it also depends on the volume and rate of usage of the file. If, for example, many accesses are being done in a random fashion (function shipping) as opposed to a set sequence of actions in which the intermediate records are not returned (program DPL).
Other things should be driving your design, such as UnitOfWork boundaries, whether access to the file is bound to logic in a program, whether or not this program will be invoked from outside of the CICS environment, etc.
Thus, in general, go with function shipping unless you detect a good reason to go down another design route.
Dig Deeper on IBM system z and mainframe systems
Related Q&A from Robert Crawford
For better mainframe capacity planning, how do I convert CPU hours to MIPS? And is there a way to calculate the relationship between MIPS and MSUs? Continue Reading
I have two years of experience in mainframe technology, currently working as a mainframe developer. I want to change to Java technology. Continue Reading
I want to replicate DB2 from the mainframe to an AIX box since it's cheaper and the copy can be used for testing. Is this possible? Continue Reading
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.