I experienced a similar performance gain by swapping a iterative REXX stem compare with a ISPF Edit Macro search. Instead of performing a one at a time comparison through 10000+ records, a FIND loop on the first 7 characters, then 6, 5, 4, etc turned a couple of thousand iterations to about 4 on average for this particular data.
Instead of thinking 'how can I code this', it is usually more efficient to think 'how would I best do this manually', then code around this approach. Cheers, MARK DOUGLAS Senior IT Support Consultant Mainframe 317 Edward Street BRISBANE QLD 4000 Ph: (07) 322 22739 Mob: 0410 937 141 Email: [email protected] Tomorrow's Queensland: strong, green, smart, healthy and fair www.towardQ2.qld.gov.au www.citec.com.au -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Jonathan Goossen Sent: Thursday, 22 March 2012 2:13 AM To: [email protected] Subject: Re: rexx cpu intensive Look at your code design and remember that REXX arrays are associative. Every access to an array element is a search for the full variable name with the index as part of the name. One of our performance people was concerned that my REXX job took 6 hours to run. I was loading a large file into an array to process it. I added monitoring of the rate at which elements were processed and found that the rate slowed from more than 100 elements per second to 2 seconds per element before I canceled it. I rewrote the REXX program to read an element and process it. This required a sort step to put the data in the order that I needed to process the data. The job then finished in 5 minutes. This redesign isn't always possible, but for me, it is possible more often then not. Thank you and have a Terrific day! Jonathan Goossen, DTM ACT Mainframe Storage Group Personal: 651-361-4541 Department Support Line: 651-361-5555 For help with communication and leadership skills checkout Woodwinds Toastmasters IBM Mainframe Discussion List <[email protected]> wrote on 03/21/2012 10:38:03 AM: > From: Tim Brown <[email protected]> > To: [email protected] > Date: 03/21/2012 10:39 AM > Subject: rexx cpu intensive > Sent by: IBM Mainframe Discussion List <[email protected]> > > What can be done to prevent REXXX programs from being so CPU intensive > > > > Thanks, > > > > Tim Brown > Systems Specialist - Project Leader > Central Hudson Gas & Electric > 284 South Ave > Poughkeepsie, NY 12601 > Email: [email protected] <<mailto:[email protected]>> > Phone: 845-486-5643 > Fax: 845-486-5921 > Cell: 845-235-4255 > > > > > This message contains confidential information and is only for the > intended recipient. 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