My dear friend Mogens, I am so glad we share the same kind of "bedtime reading" in our own parts of the world. I totally agree with you, every cache hit ratio and performance metric within Oracle needs to be 42, for us to be in a sublime and happy state...;-). After all "42" does solve all of life's problems!!
Cheers, Gaja --- Mogens N�rgaard <[EMAIL PROTECTED]> wrote: > I always thought 42 was a good number. Perhaps I was > wrong. > > Bj�rn Engsig wrote: > > >Cary Milsap from hotsos has much data to confirm an > approximate 1:100 ratio > >between LIO time and PIO time. > > > >Can we therefore conclude, that the buffer cache > hit ratio should be 99%? :-) > > > >Rgds, Bj�rn. > >On Wednesday 20 March 2002 10:48, Connor McDonald > wrote: > > > >>Some rudimentary testing on a laptop here (500Mhz, > >>512M RAM, typical single disk) > >> > >>a) visiting a single block via 4,000,000 logical > IO's > >>got me approx 35000 gets/sec > >> > >>b) repeated full table scans similar system got me > >>approx 350 phys reads/sec > >> > >>After this extensive, thorough and exhaustive > >>exercise, I can definitely say that memory access > >>versus disk access (as it pertains to Oracle) is > 100 > >>times faster on this machine in single user mode > >> > >>I think we can generalise this to be the rule for > all > >>servers under all conditions :-) > >> > >>Connor > >> > >> --- "Freeman, Robert " <[EMAIL PROTECTED]> > >>wrote: > I've heard the disk vs. memory arguments > >>before, but > >> > >>>never have seen > >>>quantifiable data either way... if anyone has > any, > >>>I'd love to see it. > >>> > >>>RF > >>> > >>>Robert G. Freeman - Oracle8i OCP > >>>Oracle DBA Technical Lead > >>>CSX Midtier Database Administration > >>> > >>>The Cigarette Smoking Man: Anyone who can appease > a > >>>man's conscience can > >>>take his freedom away from him. > >>> > >>> > >>> > >>>-----Original Message----- > >>>Sent: Monday, March 18, 2002 5:54 PM > >>>To: Multiple recipients of list ORACLE-L > >>> > >>> > >>>Robert - So THAT is the title of your next book. > I'm > >>>primed to buy it > >>>already. > >>>I just recalled a legend, maybe. "Disk is 10,000 > >>>times slower than memory, > >>>so memory access times are infinitesimal compared > to > >>>disk access". Cary > >>>Millsap covers this in his Hotsos Clinic. He has > run > >>>tests that prove "ain't > >>>so". The point is that you can't just use ratios > to > >>>tune Oracle, but need to > >>>look at wait times. > >>>Dennis Williams > >>>DBA > >>>Lifetouch, Inc. > >>>[EMAIL PROTECTED] > >>> > >>> > >>>-----Original Message----- > >>>Sent: Monday, March 18, 2002 1:04 PM > >>>To: Multiple recipients of list ORACLE-L > >>> > >>> > >>>So, does the CoO (Church of Oracle) have an > >>>infallibility doctrine then??? > >>> > >>>... From the Book of Oracle, chapter 5 ... > >>> > >>>...and the DBA did look upon his database, and he > >>>saw it was good. > >>>His tablespace datafiles being distributed tither > >>>and fro, spread amongst > >>>the > >>>platters of his disks. And he did complete that > >>>which was called > >>>documentation, > >>>and then he rested from his labors, and drank > >>>Mountain Dew Code Red... > >>> > >>>:-) > >>> > >>>Robert G. Freeman - Oracle8i OCP > >>>Oracle DBA Technical Lead > >>>CSX Midtier Database Administration > >>> > >>>The Cigarette Smoking Man: Anyone who can appease > a > >>>man's conscience can > >>>take his freedom away from him. <stuff deleted> ===== Gaja Krishna Vaidyanatha Director, Storage Management Products, Quest Software, Inc. Co-author - Oracle Performance Tuning 101 http://www.osborne.com/database_erp/0072131454/0072131454.shtml __________________________________________________ Do You Yahoo!? Yahoo! Sports - live college hoops coverage http://sports.yahoo.com/ -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Gaja Krishna Vaidyanatha INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
