Re: latch-free SCN scheme (10.1.0.3)

On Wed, 16 Feb 2005 00:56:05 -0000, Tanel P=F5der <tanel.poder.003_at_mail.ee>=  wrote:
> Btw, this description of zero-copy redo is just my untested guess, based =
on
> few parameter names, latch statistics and background information. Even
> though operating systems do use such VM page remapping tricks for (like s=
ome
> TCP stack implementations) for performance reasons - Oracle might not do
> it - zero copy might also mean that redo records are directly constructed=
 to
> private strand areas and written to disk directly from there by logwr, as
> opposed to creating these in PGA and copying to logbuffer then...

VM page remapping is not possible for a user process. I speak for Solaris and Linux. Other OSes may allow it though. Anyways, since Oracle is largely UNIXoriented,  your second scenario is more likely.

> Tanel.

Nicolai

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