Re: Tablespace/Datafile Layout for Datawarehouse

On Jun 12, 7:30 pm, EscVector <EscVec..._at_gmail.com> wrote:
> I thought that IO size was governed by the OS and MBRC simply biased
> the optimizer. http://www.ixora.com.au/tips/max_multiblock_read.htm

This depends what you mean by IO size. MBRC does change how large the request size is from the oracle standpoint. As of 10g, the largest IO request from the db is 1MB. This request may be broken up as it gets passed down the stack (OS to IO driver to storage, etc).

> There are a lot of articles about matching this up with storage
> boundaries and such, but I haven't seen large gains by doing this
> which may be because I've done it wrong :)

There isn't large gains to be had (unless it's really wrong). It's probably in the low single digit percentages.

--
Regards,

Greg Rahn
http://structureddata.org