[Default] On 7 Mar 2021 07:57:02 -0800, in bit.listserv.ibm-main reichman...@gmail.com (Joseph Reichman) wrote:
>If you read a larger number of bytes into core letÂ’s say above the bar less >I/o should speed things up no ? > If you have a large enough number of buffers, the difference should be negligible. For QSAM I hope they would be above the line taking advantage of the 31 bit address space. Having oddball data sets which require special handling and maybe even EXCP will probably cost more time than you save. Playing with BUFNO and NCP are a better expenditure of time and effort. Clark Morris > >> On Mar 7, 2021, at 10:40 AM, Radoslaw Skorupka <r.skoru...@hotmail.com> >> wrote: >> >> ?W dniu 06.03.2021 o 16:50, Laddie Hanus pisze: >>> LBI is available on DASD the largest block that will fit on 1 track, on the >>> 3390 thats about 56K. Logical record (LRECL) is still limited to 32760, >>> This is for new datasets being written. Existing datasets will read one >>> block per i/o and will be no larger than what written. this is for BSAM >>> read/check. manual DF/DSS Advanced services under the DEVTYPE macro will >>> has a table of largest blocksize per decice type >> >> The problem is I have never seen LBI block on DASD. >> Can I allocate such dataset using ISPF 3.2 or JCL DD ? >> Can I copy existing LBI dataset using IEBGENER or IDCAMS? >> >> It's more or less like long member names in PDSE. They exist, however I >> haven't found any. >> And I think it is not only my observation. >> >> From the other hand large blocks on tape are widely used and supported by >> existing system tools. >> >> Last, but not least: author of the thread wants better performance. I would >> not expect significant performance improvement by changing BLKSIZE =half >> track to whole track. >> >> -- >> Radoslaw Skorupka >> (looking for new job) >> Lodz, Poland >> >> ---------------------------------------------------------------------- >> For IBM-MAIN subscribe / signoff / archive access instructions, >> send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > >---------------------------------------------------------------------- >For IBM-MAIN subscribe / signoff / archive access instructions, >send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
