Re: buffer cache and direct reads

Mladen Gogala <gogala_at_sbcglobal.net> wrote in message news:<pan.2004.07.16.22.54.01.549074_at_sbcglobal.net>...
> On Fri, 16 Jul 2004 20:29:11 +0000, Jonathan Lewis wrote:
>
> >
> > The OP seems to be talking about Parallel Query.
> >
> > When a PX slave does a tablescan or index fast full scan,
> > it uses 'direct path reads', which do, indeed, go into local
> > memory, and bypass the buffer cache; and do get recorded
> > in v$sysstat et. al. as "physical reads direct".
> >
> > It is still possible for such blocks to appear in x$bh though,
> > as other SQL may be querying or modifying the data.
> > It is possible for PX slaves to read data (such as partitioned
> > tables, or indexed accesses into secondary tables driven
> > by the parallel scan) into the buffer cache.
>
> You, of course, are right. I have the latest marvel produced by Kirti
> and Gopal on my desk, and they seem to concur with you. It is just like
> Anjo's document about wait events in version 7, but on steroids. Great
> book!

Searching for Kirti Gopal Oracle on amazon gives the Kama Sutra, among other interesting things. While that might be entertaining, could you give a pointer to what you are actually referring to?

jg

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