Re: RAC is slower than non-RAC for batch job with lots of update/delete?

Chuck,

If you had looked little later in the book, you could have figured out the answer yourself. Look for the reference of oradebug lkdebug in chapter 12.

oradebug lkdebug -m pkey <object number> can be used to remaster an object to the current instance. You can unmaster (or dissolve remastering) the object using oradebug lkdebug -m dpkey <object number
>

Caution: Manual mastering/remastering is not supported (at least) in current versions.

-Gopal

On 10/18/07, Charles Schultz <sacrophyte_at_gmail.com> wrote:
> Yes, pgs 236-239 really spell that out quite well, thanks.
> However, I am still unclear if you can explicitly remaster a resource. From
> the verbiage, it sounds like the answer is no. Is it a feasible workaround
> to dynamically reset _gc_affinity_limit to some low value (say, 1) at the
> beginning of the batch job, than reset it afterwards? Unfortunately, this
> would also cause havoc if anything else is running on both nodes. I see that
> the affinity time and _lm_dynamic_remastering are both static parameters, so
> it would be hard to play with them unless you bounce the database.
>
> Aside from application partitioning, what is the best way to handle
> "sequential" jobs?
>
>
> On 10/18/07, K Gopalakrishnan <kaygopal_at_gmail.com> wrote:
> > Chuck,
> >
> > > I have heard that the Oracle kernel will keep track of how many times a
> gc
> > > request is made, and upon hitting a certain threshold, will remaster a
> > > particular block (or table?) to the node making a majority of the
> requests.
> > > Which makes me wonder. If your batch job is always connecting to a
> specific
> > > node, could the blocks be mastered explicitly to that node? I ask that
> of
> > > the list.
> >
> > Yes. The behavior is called Dynamic Resource Mastering. If one object
> > (or set of objects) continuously accessed in one particular node the
> > objects are mastered in that node. Check Chapter 11 (Global Resource
> > Directory) of the 10g RAC Handbook..
> >
> > There used to be some issues in the past (related to node evictions
> > during DRM) and we turn off the DRM if you are < 10.2.0.3.
> >
> > -Gopal
> >
> > --
> > Best Regards,
> > K Gopalakrishnan
> > Co-Author: Oracle Wait Interface, Oracle Press 2004
> > http://www.amazon.com/exec/obidos/tg/detail/-/007222729X/
> >
> > Author: Oracle Database 10g RAC Handbook, Oracle Press 2006
> > http://www.amazon.com/gp/product/007146509X/
> >
>
>
>
> --
> Charles Schultz

-- 
Best Regards,
K Gopalakrishnan
Co-Author: Oracle Wait Interface, Oracle Press 2004
http://www.amazon.com/exec/obidos/tg/detail/-/007222729X/

Author: Oracle Database 10g RAC Handbook, Oracle Press 2006
http://www.amazon.com/gp/product/007146509X/
--
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