On Thu, 2002-04-25 at 12:47, Curt Sampson wrote: > On Thu, 25 Apr 2002, Lincoln Yeoh wrote: > > > I think the raw partitions will be more trouble than they are worth. > > Reading larger chunks at appropriate circumstances seems to be the "low > > hanging fruit". > > That's certainly a good start. I don't know if the raw partitions > would be more trouble than they are worth, but it certainly would > be a lot more work, yes. One could do pretty much as well, I think, > by using the "don't buffer blocks for this file" option on those > OSes that have it.
I was on a short DB2 tuning course and was told that on Win NT turning off cache causes about 15-20% speedup. (I don't know what exacly is sped up :) > > [1] The theory was the drive typically has to jump around a lot more for > > metadata than for files. In practice it worked pretty well, if I do say so > > myself :). Not sure if modern HDDs do specialized O/S metadata caching > > (wonder how many megabytes would typically be needed for 18GB drives :) ). > > Sure they do, though they don't necessarially read it all. Most > unix systems Do modern HDD's have unix inside them ;) > have special cache for namei lookups (turning a filename > into an i-node number), often one per-process as well as a system-wide > one. And on machines with a unified buffer cache for file data, > there's still a separate metadata cache. ----------- Hannu ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
