Edward Jaffe wrote: | Brighter future?! BDAM is supported for 1TB EAV and getting a 'facelift' with zHPF | channel programs. Where's the 'darkness' in that? As long as your addresses are | relative and not absolute, you are AOK!
and I very largely agree. In the right hands even old-style BDAM can provide much better performance than VSAM. (The tradeoff is that one must usually write more code than would be required if VSAM were used.) New users of BDAM do, however, need to be aware of its problematic characteristics in some situations. Because of its record-preallocation scheme it should, for example, be avoided if its key space would always be very sparsely populated. There are other design alternatives to be canvassed too. In some but certainly not all cases, BSAM with NOTE and POINT can serve as well as BDAM, again at the price of more code to write or cannibalize. John Gilmore - Ashland, MA 01721, USA ---------------------------------------------------------------------- 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
