absolutely..it is VERY real life to have an access pattern that completely obliterates cache... I can't count how many shops I've known that completely glue a high end EMC to the wall and lament the fact that there is no way to disable the cache... that was on particular models, I don't claim to be an EMC expert by any means. >>>-----Original Message----- >>>From: Mercadante, Thomas F (LABOR) >>>[mailto:Thomas.Mercadante@xxxxxxxxxxxxxxxxx] >>>Sent: Thursday, September 15, 2005 12:33 PM >>>To: kevinc@xxxxxxxxxxxxx; jkstill@xxxxxxxxx; >>>cmarquez@xxxxxxxxxxxxxxxx >>>Cc: bob_murching@xxxxxxxxx; oracle-l@xxxxxxxxxxxxx >>>Subject: RE: I/O tuning... Allocating spindles to databases >>> >>>But would something like this ever really happen in real >>>life. We can all make hardware/software fail once we know >>>what its weaknesses are. >>> >>>Hell, I can make a database server fail. Quite simple >>>really. Walk into the server room and flip the breaker. >>>Shuts down every time! >>> >>>-----Original Message----- >>>From: oracle-l-bounce@xxxxxxxxxxxxx >>>[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Kevin Closson >>>Sent: Thursday, September 15, 2005 3:26 PM >>>To: jkstill@xxxxxxxxx; cmarquez@xxxxxxxxxxxxxxxx >>>Cc: bob_murching@xxxxxxxxx; oracle-l@xxxxxxxxxxxxx >>>Subject: RE: I/O tuning... Allocating spindles to databases >>> >>> >>> >>>>>>It isn't too difficult to write a simulation that will render the >>>>>>cache useless. >>> >>>actually quite easy. create a file that is 100 fold larger >>>than cache and do completely random 4KB transfers. >>> >>>smoked >>> >>> >>> >>> >>> >>> >>> >>> >>> >>>>>> >>>>>> >>>>>>-- >>>>>>Jared Still >>>>>>Certifiable Oracle DBA and Part Time Perl Evangelist >>>>>>11+ years of trying to appear to know what I'm doing. >>>>>>-- >>>>>>//www.freelists.org/webpage/oracle-l >>>>>> >>>-- >>>//www.freelists.org/webpage/oracle-l >>> -- //www.freelists.org/webpage/oracle-l