Classification: Confidential Absolutely. I plotted the curve once. It he the m/1-m curve. It escalates very very rapidly.
Simple test. Create an FB 80 80 dataset with a few thousand records in it and read the datasets. Create a FB 80 27920 dataset with the fame number of records and compare the stats. Also watch the space quantity required. HTH, -----Original Message----- From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of Roger Bolan Sent: Sunday, January 19, 2025 7:56 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Does this make any sense? [CAUTION: This Email is from outside the Organization. Unless you trust the sender, Don’t click links or open attachments as it may be a Phishing email, which can steal your Information and compromise your Computer.] Decades ago, when some of us were first learning to code in C, we found a significant improvement in performance when we switched the datasets we were using for I/O from unblocked to blocked records. So it does make sense. On Sun, Jan 19, 2025 at 4:13 PM Michael Oujesky <reflect...@oujesky.net> wrote: > I would suspect KSDS VSAM files that were being accessed randomly > without LSR processing. Use of LSR or conversion to sequential > processing is the suspected tweak. > > Michael > > At 09:06 AM 1/19/2025, Robert Prins wrote: > > > From LinkedIn: > > > ><quote> > >2 weeks ago I received the analysis data from a new client that > >wanted to reduce their CPU consumption and improve their performance. > >They sent me the statistical data from their z16 10 LPARS. > >Information about 89,000+ files. I analyzed their data and found > >2,000+ files *that could be > improved* > >and would save CPU when improved. *I pulled out 1 file to demonstrate > >a Proof of Concept (POC) for the client. I had the client run the POC > >and it showed a 29% reduction in CPU every time that file will be > >used. The 29% did not include 3 other major adjustments that would > >save an addition 14% CPU and cut the I/O by 75%.* This is just 1 > >file. The other files can save 3% to 52% of their CPU every time they are > >used in BATCH or ONLINE. > ></quote> > > > >I've been a programmer on IBM since 1985, and the above doesn't make > >any sense to me, how can changing just one file result in a 43% > >reduction in CPU usage? > > > >I've only ever been using PL/I, and using that I did manage to make > >some improvements to code, including reducing the CPU usage of a CRC > >routine by an even larger amount, 99.7% (Yes, ninety-nine-point-seven > >percent), but that was because the old V2.3.0 PL/I Optimizing > >compiler was absolute > shite > >at handling unaligned bit-strings, but WTH can you change about a > >file to get the above reduction in CPU? > > > >Robert > >-- > >Robert AH Prins > >robert(a)prino(d)org > >The hitchhiking grandfather > ><https://apc01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpr > >ino.neocities.org%2Findex.html&data=05%7C02%7Callan.staller%40hcltech > >.com%7C753b09999ba143824db308dd38f5b285%7C189de737c93a4f5a8b686f4ca99 > >41912%7C0%7C0%7C638729350138800803%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU > >1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIld > >UIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=bIqyRpVxpD3ooWlXNu50WXZ1KBU8iIKwrV5T > >n2zl3WE%3D&reserved=0> > >Some REXX code for use on z/OS > ><https://apc01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpr > >ino.neocities.org%2FzOS%2FzOS-Tools.html&data=05%7C02%7Callan.staller > >%40hcltech.com%7C753b09999ba143824db308dd38f5b285%7C189de737c93a4f5a8 > >b686f4ca9941912%7C0%7C0%7C638729350138824522%7CUnknown%7CTWFpbGZsb3d8 > >eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiT > >WFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=R%2BREfSccCBAYHGVCGs7Zebqt > >nawn%2BidazanwwFIoXAg%3D&reserved=0> > > > >--------------------------------------------------------------------- > >- 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 ::DISCLAIMER:: ________________________________ The contents of this e-mail and any attachment(s) are confidential and intended for the named recipient(s) only. 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