All, >From a performance POV I have to say I favour PDSE over PDS. I've had two experiences that affected the business end of the companies I was looking at.
One was a PDS Source Library with around 25,000 members that were check-out/in all day by a couple of hundred programmers. It was the single busiest dataset in the whole shop (two sites, 10 CEC, 19 LPARS, several 1000 ESCON Channels). Changing this to PDS-E, and assuring PDSE caching was working (old style DFSMS 1.2 or 1.3 with MSR=3ms) took this dataset off the RADAR and satisfied some series latent demand on that Development system. Second and more recent example was a transaction-in-batch job with 45 steps and a SLA of 10 second average. Converting the main application loadlibs to PDS-E shaved several seconds off the average elapsed time (the customer did not specify), and later adding PDSE caching with VLF sliced off another 2-3 seconds. For my own datasets it is just that I hate interrupting what I'm doing with a compress. I've gone over three years without compressing a PDS, because my personal datasets are PDSE. Ron > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf Of > Chris Craddock > Sent: Wednesday, February 10, 2010 6:44 PM > To: IBM-MAIN@bama.ua.edu > Subject: Re: [IBM-MAIN] PDS vs. PDSE > > On Wed, Feb 10, 2010 at 1:46 PM, John R. Ehrman (408-463-3543 T/543-) < > ehr...@vnet.ibm.com> wrote: > > > PDSEs have been available for a long time, and provide many > > advantages over PDSs. Why are people reluctant to use PDSEs? > > > > > As others have pointed out, PDSEs have a (justifiably) bad reputation for > poor reliability and performance. They also have a litany of limitations > (e.g. not being able to be used in the IPL-time LPA) that make them less > useful and/or more complex to deal with than a plain old PDS. Which is > doubly ironic since it was the limitations of PDSs that drove the creation > of PDSE in the first place. It is another example of a piece of half > baked/underfunded functionality where marketing factors trumped business > needs (e.g. the completely artificial need for PDSEs to be SMS managed) and > nobody took the time (i.e. there was no budget) to stitch them into the > operating system and utilities so that they could actually be used as a > replacement for PDSs. > > With all that said, the straw man arguments in favor of cross-system sharing > of PDS over PDSE demonstrate a lack of understanding of the fundamental > limitations of the former. For all their faults, PDSEs are actually a better > deal for sharing within a SYSPLEX and for most garden variety purposes they > work just fine these days. Assuming you keep up with maintenance :-) > > -- > This email might be from the > artist formerly known as CC > (or not) You be the judge. > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO > Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
