> One question I would liked answered by the experts is why now with > 64-bit storage one would choose to use a hiperspace (or dataspace) over > just using storage above the bar?
TYPE=CACHE hiperspaces continue to provide a function that z/OS has not provided with 64-bit memory objects. With TYPE=CACHE, the data you write to the hiperspace remains in real storage (prior to zArchitecture, it was in expanded storage) unless the system needs to steal that storage. When the storage does need to be stolen, the system takes it without paging the data out to aux . The data is lost, and presumably the user has another copy of it somewhere. HiperBatch is one thing that uses TYPE=CACHE hiperspaces. Although I don't know how much HiperBatch is used these days. For QSAM, if zHPF is being used, HiperBatch will not be used (which was done to avoid the development cost of implementing HiperBatch for QSAM zHPF). So you can have the I/O performance improvement from zHPF for QSAM, or the I/O reduction from HiperBatch caching for QSAM, but not both. im Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
