Howard, Yes, I agree, having the BLLSIZE=0 is the way to go now.
However effective use of BUFNO on the DD can really increase efficiencies when you add enough buffers to match devices transfer sizes, without going overboard on it. I've done some tinkering over the past few years and it appears that 128K to 1M of buffering per file seems to cover most devices well. So you don't always have to change that in the JCL, just find a good value for BUFNO that applies well to most devices and use the BLKSIZE=0 to get the max block size for the device. I will disagree with the statement that efficiencies should not be in programs or in Jobs. Sometimes it's needed. Darren -----Original Message----- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Howard Brazee Sent: Tuesday, October 30, 2007 8:57 AM To: IBM-MAIN@BAMA.UA.EDU Subject: Re: z/OS 1.9 Features summary On 30 Oct 2007 08:47:17 -0700, [EMAIL PROTECTED] (GAVIN Darren * OPS EAS) wrote: >Actually that can be done already, on FB files one can read in the >entire block into a program, by using the block size as the record >length. However Cobol LE forces DCB matching, so not sure how that gets >turned off to allow for it. > >As to the BLKSIZE and LRECL parameters being archaic, they really are >not obsolete. I love "BLOCK CONTAINS 0" as an attempt to solve this problem. >They are there for efficiency reasons. This kind of efficiency should not be in programs nor even jobs anymore. Switching a file from one disk to another with a different format should not require any JCL change as the OS picked the best blocksize at the new location. ---------------------------------------------------------------------- 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
