IBM APAR OA47689, PTF UA90982, introduces a new operating system function known as the ‘Data Set Optimization Configuration’. A new PARMLIB member, IEFOPZxx, allows the user to define the data set optimization configuration, and specify which executable programs are to be processed (optimized). For example, this could provide a list associating old COBOL load libraries with the intended new load libraries (one for each desired architecture level).
OLDNEW processing provided by the new function allows a site to define OLD and NEW data sets that facilitate conversion of applications from an OLD data set name to a NEW data set without JCL changes. During allocation when an OLD data set is found allocated to a JOBLIB/STEPLIB (or other user defined DD statement) the associated NEW data set is concatenated in front of the OLD data set.
How does z/OS ‘Data Set Optimization Configuration’ impact CA PDSMAN processing?
z/OS Environments that have the Data Set Optimization function active.
In general, use of this new function does not impact PDSMAN in any way. The OLDNEW processing is performed during allocation. So when PDSMAN subsequently front-ends the BLDL SVC, for example, the NEW data set is already allocated and participates in PDSMAN rule lookups like any other data set.
However, there are a couple of cases that may require attention:
- The default processing of the Data Set Optimizer function when an old data set is managed by LLA is to also place the associated new data set into LLA. So you may need to add a $LLA rule to PDSMINIT that matches the new data set.
- Use of the PDSMAN Program Fetch Optimization facility ($PFO LIB= rules) may be impacted by introduction of additional libraries into a concatenation. This is because a common use of Data Set Optimization is to ease migration to COBOL V5, which requires Program Object libraries (PDSE libraries) be used to house the resulting executables. This could effectively disable $PFO rules for some concatenations (see below).
The following is extracted from the PDSMAN LLA/Extensions and Performance Facilities User Guide:
When a STEPLIB concatenation includes a PDSE library, PFO processing is performed only when every data set in the concatenation has a matching $PFO control statement that enables PFO processing.