Ocfs users - May 2004 - Follow up on async I/O question

Sunil Mushran wrote:
>And as that gets into reading debugocfs outputs, the user has to make
the determination, if the effort is worth the gain in performance. Why
only logfiles? Well, because Oracle performs large ios only to the
logfiles. The ios to be datafiles are in smaller chunks. Hope this
helps. Sunil 


I'd like to point out a small mistake in this post.  Oracle most
certainly performs large IOs to more
than just logfiles.  Parallel Query and normal foreground processes
alike perform multiblock IO.
They are known as direct path read and write, scattered read and others
and are driven by full scans,
index range scans, foreground temp segment IO, recovery and so on.



Kevin Closson
Chief Architect, Database Solutions
PolyServe, Inc
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indeed, 1mb on full scans etc.
and on create datafile

On Wed, May 26, 2004 at 08:42:05AM -0700, Kevin Closson
wrote:
> 
> Sunil Mushran wrote:
> >And as that gets into reading debugocfs outputs, the user has to make
> the determination, if the effort is worth the gain in performance. Why
> only logfiles? Well, because Oracle performs large ios only to the
> logfiles. The ios to be datafiles are in smaller chunks. Hope this
> helps. Sunil 
> 
> 
> I'd like to point out a small mistake in this post.  Oracle most
> certainly performs large IOs to more
> than just logfiles.  Parallel Query and normal foreground processes
> alike perform multiblock IO.
> They are known as direct path read and write, scattered read and others
> and are driven by full scans,
> index range scans, foreground temp segment IO, recovery and so on.
> 
> 
> 
> Kevin Closson
> Chief Architect, Database Solutions
> PolyServe, Inc
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