I do not object at all to the buffering products which are used to compensate for VSAM applications where the programmers know nothing about VSAM and allocate them with no consideration to performance. As an aside, I have also found Systems Programmers have little clue about VSAM files and blindly follow IBM recommendations when they install system level software which needs VSAM files. A running product which dynamically adjusts the buffers will forgive many sins.
I’d like to offer some other alternatives. One is to train staff in the use of VSAM and what are good VSAM files and what are not so good ones. Besides performance considerations, there are space allocations which can be outrageous because of inefficient CI and CA sizes BUT they still work for the application. I can hear the moans and groans already from all over the world saying something like, “Ya, Jim, you are an old guy who lived through all this but we have more important things to do getting all this Web stuff working on the mainframes, etc”. This was the same argument I used back in the 20th Century getting all the things updated from MVT to MVS to XA to ESA to OS390. Usually I do not tell stories but this one will make a point. In 1975 I was in the Air Force in Colorado and got grabbed to come to the Pentagon to be trained as a MVT Sysprog. The person I replaced was Sgt Ron Ferguson who decided to exit after 4 years to make big bucks as a Contractor eventually working for Boeing Computer Services. Ron got in on the ground floor of VSAM and stayed in it for his whole career. A number of you folks may have heard of Ron who became the almost world’s expert in VSAM. He was consulting, teaching all over and eventually founded his own firm SIS which later became Mainstar and then he sold out to Rocket Software. Along the way Ron was asked to clone himself because the demand for VSAM consulting and classes taught was greater than Ron could handle. In the late 1980s, Artificial Intelligence was the rage. In 1991-2000 after retiring from the Air Force I was working at Treasury with a big “paying” customer using VSAM and it was my wife. She’d come home and complain about her VSAM performance or maybe just how could she get her batch jobs to run faster. I am not plugging this product but I would have loved to have thought of it. Mainstar offered a software product called VSAM Manager. It was the collective Artificial Intelligence of Ron built into a product which would read the VSAM file structure and give you recommendations about CISIZE, CASIZE, buffers, splits, etc. It also would show you were the splits occurring to give you a better idea of what was happening inside the file. My wife could invoke this simple utility, take the recommendations, REORG the files, and instantly she saved bunches of space and her jobs screamed (I/O’s were reduced and elapsed times were really reduced). I had one happy customer and peace at home. I also found out veteran Sysprogs had system stuff using VSAM files which were eating our lunch. Ron’s product convinced even the most skeptical Sysprog how things could be improved and there was no need to guess and hope it helped. So it depends on what someone wants to improve. I needed to get performance gains and also reduce DASD space. Even folks who thought they knew VSAM were amazed at the critique and recommendations from Ron’s Wisdom. People can try a number of ways to solve the VSAM issue in any shop. I know the way I would go if I had to do it all over again. Oh yes, as I said Ron sold Mainstar and I understand retired in the Seattle area and bought his very own Tug Boat to do things like chugging to Alaska. Jim ---------------------------------------------------------------------- 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
