Re: Buffer Waits
hmm, could you go into a bit detail on the light-scan? I have a DSS system but I am not sure how to make it use light scan. I read something on the book about it, but it wasn't very clear on exactly how to utilize it or how to check it. thanks yan Bob Davis wrote: > In article <79qhb8$fi$1@news.xmission.com>, > Dale Forrey <forrey@wsu.edu> wrote: > > > > Does a properly tuned Informix instance used primarily for decision > > support have a buffer wait count near 0? I am working on a relatively > > small data warehouse running on a 2 processor RS/6000 with 512 meg of real > > memory. I tried increasing the number of buffers but that had little > > effect. I increased the LRUS from 4 to 8 and that had a noticeable effect. > > But from what I have read increasing LRUS will eventually have a > > detrimental effect on processing. What else should I be trying. Thanks > > for you help. > > > > Dale Forrey, DBA email: forrey@wsu.edu > > Information Technology FAX: (509) 335-0540 > > Washington State University Phone: (509) 335-7098 > > PO Box 641222 > > Pullman, WA 99164-1222 > > > > ADABAS 6.2.1 on OS/390 > > Natural 2.2.8 > > Predict 3.4.1 > > > > Informix 7.30 UC3-1 on AIX 4.3.1 > > > > A low buffer wait count is a good thing. As long as you are seeing good > performance don't try to fix what ain't broke. :-) > > A really well tuned DSS system could theoretically use nothing but light scans > and skip the buffer pool entirely. > > Bob > ------ > > -----------== Posted via Deja News, The Discussion Network ==---------- > http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
In article <79umtl$8ko$1@news.xmission.com>, "Yan Zhu" <yan.zhu@infinity-insurance.com> wrote: > > > hmm, could you go into a bit detail on the light-scan? I have a DSS system but I > am not sure how to make it use light scan. I read something on the book about it, > but it wasn't very clear on exactly how to utilize it or how to check it. > thanks > yan Yan, Look at today's posting by Chuck Renaud. I don't believe I can give you any more/better information on light scans than he does. Bob ------- > > Bob Davis wrote: > > > In article <79qhb8$fi$1@news.xmission.com>, > > Dale Forrey <forrey@wsu.edu> wrote: > > > > > > Does a properly tuned Informix instance used primarily for decision > > > support have a buffer wait count near 0? I am working on a relatively > > > small data warehouse running on a 2 processor RS/6000 with 512 meg of real > > > memory. I tried increasing the number of buffers but that had little > > > effect. I increased the LRUS from 4 to 8 and that had a noticeable effect. > > > But from what I have read increasing LRUS will eventually have a > > > detrimental effect on processing. What else should I be trying. Thanks > > > for you help. > > > > > > Dale Forrey, DBA email: forrey@wsu.edu > > > Information Technology FAX: (509) 335-0540 > > > Washington State University Phone: (509) 335-7098 > > > PO Box 641222 > > > Pullman, WA 99164-1222 > > > > > > ADABAS 6.2.1 on OS/390 > > > Natural 2.2.8 > > > Predict 3.4.1 > > > > > > Informix 7.30 UC3-1 on AIX 4.3.1 > > > > > > > A low buffer wait count is a good thing. As long as you are seeing good > > performance don't try to fix what ain't broke. :-) > > > > A really well tuned DSS system could theoretically use nothing but light scans > > and skip the buffer pool entirely. > > > > Bob > > ------ > > > > -----------== Posted via Deja News, The Discussion Network ==---------- > > http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own > > -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own