Some other things I have observed. Sequentially searching large arrays for each input record, when the input data set contained 100,000's of records. Use of DISPLAY DECIMAL or COMP-3 subscripts instead of INDEX's or at the very least using a COMP subscript.
Switching to SEARCH ALL and INDEX's can save large amounts of wall clock time and CPU time. -----Original Message----- From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of R.S. Sent: Thursday, April 23, 2020 7:35 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: [External] Re: Here we go again; [External Email. Exercise caution when clicking links or opening attachments.] Adam, Believe me or not, but I (my folks) saved a lot of space by changing BLKSIZE to correct one, means SDB. It was not only JCL, but also COBOL. What is "a lot of space"? It was enough free space on our huge 500GB DASD box to NOT PURCHASE ANOTHER BOX. Multiply it x2, because we used PPRC. We also saved a lot of space by elimination of redundant jobs and datasets. However the main goal was to make batch time shorter. Few years later we saved a lot of space by using extended format PS and compression - for selected datasets. Few years ago we saved a lot of space by using zEDC almost everywhere. Optimization is still valid, even today. It was extremely valid 30 or years ago due to DASD capacity and prices. We did it, we do it, we will do it. -- Radoslaw Skorupka Lodz, Poland ====================================================================== Jeśli nie jesteś adresatem tej wiadomości: - powiadom nas o tym w mailu zwrotnym (dziękujemy!), - usuń trwale tę wiadomość (i wszystkie kopie, które wydrukowałeś lub zapisałeś na dysku). Wiadomość ta może zawierać chronione prawem informacje, które może wykorzystać tylko adresat.Przypominamy, że każdy, kto rozpowszechnia (kopiuje, rozprowadza) tę wiadomość lub podejmuje podobne działania, narusza prawo i może podlegać karze. mBank S.A. z siedzibą w Warszawie, ul. Senatorska 18, 00-950 Warszawa,www.mBank.pl, e-mail: kont...@mbank.pl. Sąd Rejonowy dla m. st. Warszawy XII Wydział Gospodarczy Krajowego Rejestru Sądowego, KRS 0000025237, NIP: 526-021-50-88. Kapitał zakładowy (opłacony w całości) według stanu na 01.01.2020 r. wynosi 169.401.468 złotych. If you are not the addressee of this message: - let us know by replying to this e-mail (thank you!), - delete this message permanently (including all the copies which you have printed out or saved). This message may contain legally protected information, which may be used exclusively by the addressee.Please be reminded that anyone who disseminates (copies, distributes) this message or takes any similar action, violates the law and may be penalised. mBank S.A. with its registered office in Warsaw, ul. Senatorska 18, 00-950 Warszawa,www.mBank.pl, e-mail: kont...@mbank.pl. District Court for the Capital City of Warsaw, 12th Commercial Division of the National Court Register, KRS 0000025237, NIP: 526-021-50-88. Fully paid-up share capital amounting to PLN 169.401.468 as at 1 January 2020. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN Confidentiality notice: This e-mail message, including any attachments, may contain legally privileged and/or confidential information. If you are not the intended recipient(s), or the employee or agent responsible for delivery of this message to the intended recipient(s), you are hereby notified that any dissemination, distribution, or copying of this e-mail message is strictly prohibited. If you have received this message in error, please immediately notify the sender and delete this e-mail message from your computer. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
