Re: Concurrent i/o

Matthias Hoys wrote:
>
> Hi,
>
> Is anyone using Oracle 10g on AIX with filesystems mounted for concurrent
> i/o (instead of the default cached i/o) ? Just wanted to know if there are
> any known disadvantages. Apparently concurrent i/o has nearly the
> performance of raw devices.
>
> Thanks
> Matthias

If "concurrent" is equivalent to "direct" IO, then you'll want to ensure that your buffer cache is sized appropriately. Many people have converted to raw (or equivalent) and been disappointed because they have not taken the loss of file system cache into account (and increased their buffer cache accordingly)

hth

-- 
Connor McDonald
Co-author: "Mastering Oracle PL/SQL - Practical Solutions"
Co-author: "Oracle Insight - Tales of the OakTable"

web: http://www.oracledba.co.uk
web: http://www.oaktable.net
email: connor_mcdonald_at_yahoo.com


"Semper in excremento, sole profundum qui variat."

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