z/OS 1.12 has a new ALLOC parameter that is supposed to improve DB2 start-up times when it's got zillions of files too:
SYSTEM MEMDSENQMGMT(ENABLE) This option re-jigs allocation/de-allocation processing to make it more efficient when lots of files are allocated. Ant. -----Original Message----- From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf Of W. Kevin Kelley Sent: Thursday, 28 October 2010 10:59 AM To: IBM-MAIN@bama.ua.edu Subject: Re: z/os 1.11 and low private On Tue, 26 Oct 2010 17:27:47 -0400, Knutson, Sam <sknut...@geico.com> wrote: >Even though it is not the default with appropriate testing no one should be afraid of setting USEZOSV1R9RULES(NO). >This is going to have a positive impact on performance in select tasks. Sam, We specifically looked at the performance of USEZOSV1R9RULES(NO) as part of our Mean Time To Recovery (MTTR) efforts. During our testing, we simulated DB2 opening a very large number (100K) of VSAM data sets. USEZOSV1R9RULES(NO) made a noticeable difference, and that difference was proportionately greater as the number of data sets being opened was increased. USEZOSV1R9RULES(NO) is certainly something that we would recommend to anyone who wants to reduce their DB2 start-up time. W. Kevin Kelley -- IBM POK Lab -- z/OS Core Technical Development ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu 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 lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
