I don't even know how to subset this message to formulate a response. So, I'm replying intact.
But, my point is, while the percentage may not believed, how many users write access methods, terminal handlers, abend handlers, DB2 optimisers, ENQ-Handlers, operator commands, interupt handlers, message passers, or any other system function. These functions are requested by programmes, operators, terminal users, or whatever. Empirical data has shown, to me at least, including statements from IBM, that the user code is a small part of this. So, what is the point, on today's fast machines, about worrying about the optimisation of the small stuff? Yes, you can drive a z/Box nuts with poorly indexed DB's or bad loops. But, are these faults caused by the language, or bad programmers, DBA's, or others? - Too busy driving to stop for gas! -----Original Message----- From: Mark Zelden <mzel...@flash.net> Sender: IBM Mainframe Discussion List <IBM-MAIN@bama.ua.edu> Date: Fri, 25 Jun 2010 15:33:05 To: <IBM-MAIN@bama.ua.edu> Reply-To: IBM Mainframe Discussion List <IBM-MAIN@bama.ua.edu> Subject: Re: Delete all members of a PDS that is allocated On Fri, 25 Jun 2010 15:25:58 -0500, McKown, John <john.mck...@healthmarkets.com> wrote: >> -----Original Message----- >> From: IBM Mainframe Discussion List >> [mailto:ibm-m...@bama.ua.edu] On Behalf Of Mark Zelden >> Sent: Friday, June 25, 2010 3:21 PM >> To: IBM-MAIN@bama.ua.edu >> Subject: Re: Delete all members of a PDS that is allocated >> >> On Fri, 25 Jun 2010 19:42:27 +0000, Ted MacNEIL >> <eamacn...@yahoo.ca> wrote: >> >> > >> >In a z/OS environment, with access methods, online >> sub-systems, utilities, >> and the like, less than 5% of the code running on the z/Box >> is user-written. >> > >> >> Where did you get that statistic from? >> >> Mark >> -- > >And does it mean: "5% of the CPU resource used on a z/OS system is consumed by user written code" or "5% of the number of lines of code for all the executable programs on a given z/OS system are user written." From context, I would guess the former. > With all the recovery code written into the OS, subsystems and ISV software, I would think the latter if anything (but I find that a hard to believe number also, but could be close to that in a small shop I guess). The system idles quite nicely at very low utilization, so saying that running production and development environments at or near 100% (which most cost conscience shops do) isn't because of "user written code" just because it invokes access methods, system services, CICS services, SQL or whatever would be a very misleading statement IMO. Mark -- Mark Zelden - Zelden Consulting Services - z/OS, OS/390 and MVS mailto:mzel...@flash.net Mark's MVS Utilities: http://home.flash.net/~mzelden/mvsutil.html Systems Programming expert at http://expertanswercenter.techtarget.com/ ---------------------------------------------------------------------- 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
