Detect which PDS should be changed to PDSE.

[Shahid]

Hi,

There are number of PDS which we are using for many libraries, for JCLs, PROCs and source code. But many of them are PDS, when I suggested them to use PDSE instead, no body responded. I was just thinking if I can figure out what are the PDS which can be converted to PDSE for better use of them, it might help to convince them.

There are also LOADLIBs which needs to be compressed every now and then. What is the best way to avoid it?

[Robert Sample]

There are a handful of PDS data sets that CANNOT be converted to PDSE -- SYS1.PARMLIB, SYS1.PROCLIB, SYS1.LINKLIB and LPA data sets for example (these data sets are allocated and accessed before the started task that supports PDSE -- usually SMSPDSE -- is running). Work with your site support group -- they should know which PDS cannot be converted. The best way to avoid the need to compress a LOADLIB is to convert it to PDSE as they never need to be compressed.

[Shahid]

Thanks Robert.

Should there be any caution taken before converting loadlib to PDSE?

[Robert Sample]

I don't know that caution is needed, but there are a few points worth mentioning.
- A PDSE may require more space than the equivalent PDS, so if space is limited then a PDSE might not be a good choice.
- PDSE uses program objects while PDS use load modules. The conversion between the two is done automatically during copy.
- Some program objects cannot be converted to load modules, so once PDSE starts being used there is a possibility that the conversion is one-way. This would typically not be an issue unless the site is compiling programs into the PDSE since load modules converted to program objects can be converted back -- it's only program objects that use features not available to load modules that would be a problem.