Ricc, DLF is not designed for PDS, and you can inadvertently create integrity problems across two or more LPARS when you use RETAIN.
If the dataset remains a PDS and you suspect that a large amount of the activity on the dataset is BLDL then you will realize some benefit by placing the dataset in LLA as FROZEN. There has been a lot of discussion in the recent past as to whether this is supported, but there was consensus that it works for PDS. This will not cause any member caching to take place unless the access is with Fetch, but eliminating the directory IO is often enough to take the bulls eye of these datasets. Ron > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of > Ricc Harding > Sent: Tuesday, January 11, 2011 10:21 AM > To: [email protected] > Subject: [IBM-MAIN] DLF - DLFCLASS Using DLF for PDS data? > > Since a search of the archives for DLFCLASS got no hits, I am guessing this > has not been discussed much. One of the clients products has a small PDS > updated infrequently, accessed simultaneously by many people all the time > (125,000 accesses in a normal hour), and a point of device contention and > such often even though all access is read only. > > I thought I would try and load the dataset as a DLF object and eliminate > much of the physical device contention. But since it is a PDS (less than a > 100 members and about 1 cylinder in size) it does not appear that DLF will > have any benefit (DLF is QSAM or VSAM only) since it looks like they open > the PDS, then FIND the member, then READ it. > > VLF seems to do the same as DLF but allows PDS format data. > > Does anyone have experience using either VLF or DLF for some other than the > predefined IBM classes (in other words defining your own class and > populating it). > I would like to avoid gotcha's that others have hit if there are any. > aTdHvAaNnKcSe > Ricc > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] 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 [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
