Peter, Review/research the COBOL compiler FASTSRT option. If you are using it what you suggest will possibly make things worse.
If you aren't using it, it may be a cleaner solution that recoding JCL. to achieve the desired savings. Alan Field Technical Engineer Principal BCBS Minnesota Phone: 651.662.3546 Mobile: 651.428.8826 From: "Farley, Peter x23353" <[email protected]> To: [email protected], Date: 11/25/2013 09:43 Subject: Has anyone measured CPU savings using external SORT's vs internal (COBOL) SORT's? Sent by: IBM Mainframe Discussion List <[email protected]> It has been suggested to management here that there could be potentially significant CPU savings from re-engineering application programs such that any SORT's are done in a separate step, so that a program with a single internal SORT would be broken up into a pre-SORT process followed by an external SORT of the massaged data followed by a post-process of the SORTed data. The first obvious factor is that SORT (at least Syncsort and DFSORT) are *far* more efficient at I/O than any COBOL program can be. It is also obvious that the data volume would affect the relative CPU cost of the two methods, with small volume possibly favoring an internal SORT and large(r) volume possibly favoring the external SORT process, FSVO "large(r)". Compressed (z/OS compression, not disk subsystem compression) vs non-compressed data files could also be another factor in CPU differences. Has anyone else been asked to measure whether this claim is true or not, and if true where the "break" point in volume might be? TIA for any insight you can provide. Peter -- This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
