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Well, the point of the tip was that one can minimize the impact of journaling by implementing commitment control. Of course, this would seem to be irrelavent to this particular thread... Anyway, the article that Vern referenced (by Rick Turner), is full of all sorts of great performance enhancing guidelines. Here's the updated link: http://www-1.ibm.com/support/docview.wss?uid=nas106f669c96c492f6a86256d6c006 4adbe&rs=110 Eric DeLong Sally Beauty Company MIS-Project Manager (BSG) 940-898-7863 or ext. 1863 -----Original Message----- From: rob@xxxxxxxxx [mailto:rob@xxxxxxxxx] Sent: Friday, January 21, 2005 2:28 PM To: Midrange Systems Technical Discussion Subject: RE: slow runs Well, that wasn't exactly what I wanted to hear. I was hoping to hear that I didn't have to do 'x' to get journalling to perform as well as not journalling. I was hoping to hear that just journalling increased speed, failing that, not that it degraded it. Rob Berendt -- Group Dekko Services, LLC Dept 01.073 PO Box 2000 Dock 108 6928N 400E Kendallville, IN 46755 http://www.dekko.com "DeLong, Eric" <EDeLong@xxxxxxxxxxxxxxx> Sent by: midrange-l-bounces@xxxxxxxxxxxx 01/21/2005 03:09 PM Please respond to Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx> To "'Midrange Systems Technical Discussion'" <midrange-l@xxxxxxxxxxxx> cc Subject RE: slow runs I think it allows for asynchronous writes, but I can't remember what was special about it.... Oh yeah! I found it in my saved tips folder... <BEGIN SNIP> From: Vern Hamberg [vhamberg@xxxxxxxxxxxxxxxxxxxxxxxxx] Sent: Thursday, May 01, 2003 9:48 AM To: Midrange Systems Technical Discussion Subject: Re: Journal performance problems There's a little-known solution - turn on commitment control. Without this, jobs can take 3-4 times as long to finish. Here's an extract from an article by Rick Turner: Commitment Control & Journaling Though most database and other write operations are asynchronous, database journal receiver write operations are usually synchronous to the issuing job. This means the job is forced to wait (in the system's disk I/O write functions) for the I/O (write) to complete before it continues processing. The SLIC Journal functions can do the journal writes asynchronously if the job uses commitment control. When commitment control is in effect, the database journal write functions know that file integrity is required only at a commit boundary and not at every record update/add/delete operation. Because of this, the database journal writes are scheduled asynchronously. When a commit boundary is reached, the database functions ensure that all pending database file I/O is complete before continuing. Lab tests show that using commitment control and journaling yields performance almost equal to not using database journaling. If you use journaling but not commitment control, a job can be three to four times slower than when you don't use journaling at all. "But this means I have to change my code!" you say. True, but the cost of the changes are minimal compared to the performance benefit. In the CL program that calls the batch program, specify the files that use commitment control and open them. Start a commit cycle in the CL program before calling the batch program. In the application program(s), change the file description to specify that commitment control is in use. Once the program returns to the CL program, end the commit cycle to force any pending file I/O to complete. There's more in the article, including side effects of SMAPP on journaling performance, available at < http://www-1.ibm.com/support/docview.wss?uid=nas1e907e76673a614dd86256a2900 54f546&rs=110> HTH Vern <END SNIP> Eric DeLong Sally Beauty Company MIS-Project Manager (BSG) 940-898-7863 or ext. 1863 -----Original Message----- From: rob@xxxxxxxxx [mailto:rob@xxxxxxxxx] Sent: Friday, January 21, 2005 12:26 PM To: Midrange Systems Technical Discussion Subject: RE: slow runs Sounds familiar... Rob Berendt -- Group Dekko Services, LLC Dept 01.073 PO Box 2000 Dock 108 6928N 400E Kendallville, IN 46755 http://www.dekko.com "Ingvaldson, Scott" <SIngvaldson@xxxxxxxxxxxx> Sent by: midrange-l-bounces@xxxxxxxxxxxx 01/21/2005 12:02 PM Please respond to Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx> To <midrange-l@xxxxxxxxxxxx> cc Subject RE: slow runs Doesn't journalling automagically enable concurrent writes, or something like that? Regards, Scott Ingvaldson iSeries System Administrator GuideOne Insurance Group -----Original Message----- date: Fri, 21 Jan 2005 11:20:50 -0500 from: rob@xxxxxxxxx subject: Re:slow runs I've heard that journalling can make things run faster. I forget why. Rob Berendt -- Group Dekko Services, LLC Dept 01.073 PO Box 2000 Dock 108 6928N 400E Kendallville, IN 46755 http://www.dekko.com "Muralidhar Narayana" <Muralidhar_Narayana@xxxxxxxxxxx> Sent by: midrange-l-bounces@xxxxxxxxxxxx 01/21/2005 11:05 AM Please respond to Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx> To <midrange-l@xxxxxxxxxxxx> cc Subject Re:slow runs Nothing else in running at same time , Iam doing testing, I have stopped others jobs. Iam tryiung to find out how this could make difference and what are the factors that are going to influence? -- This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list To post a message email: MIDRANGE-L@xxxxxxxxxxxx To subscribe, unsubscribe, or change list options, visit: http://lists.midrange.com/mailman/listinfo/midrange-l or email: MIDRANGE-L-request@xxxxxxxxxxxx Before posting, please take a moment to review the archives at http://archive.midrange.com/midrange-l. -- This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list To post a message email: MIDRANGE-L@xxxxxxxxxxxx To subscribe, unsubscribe, or change list options, visit: http://lists.midrange.com/mailman/listinfo/midrange-l or email: MIDRANGE-L-request@xxxxxxxxxxxx Before posting, please take a moment to review the archives at http://archive.midrange.com/midrange-l. -- This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list To post a message email: MIDRANGE-L@xxxxxxxxxxxx To subscribe, unsubscribe, or change list options, visit: http://lists.midrange.com/mailman/listinfo/midrange-l or email: MIDRANGE-L-request@xxxxxxxxxxxx Before posting, please take a moment to review the archives at http://archive.midrange.com/midrange-l. -- This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list To post a message email: MIDRANGE-L@xxxxxxxxxxxx To subscribe, unsubscribe, or change list options, visit: http://lists.midrange.com/mailman/listinfo/midrange-l or email: MIDRANGE-L-request@xxxxxxxxxxxx Before posting, please take a moment to review the archives at http://archive.midrange.com/midrange-l.
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