Re: Oracle with multiple CPUs

I agree with Barbara,

However, in answer to the questions,

1. Yes there are init.ora parameters to set, parallel_min_servers, parallel_max_servers, and there are others you may want, check the reference manual.
2. There are no problems with altering a table to add or reduce degree's of parallelism. As far as benefits, what we are discussing here is generally called Parallel Query, which will only come into play when using hints or, becomes the default behavior when a table has degee's of parallelism and a full table scan is chosen in the execution plan of a query. So if your application has tables with large numbers of rows and queries perform frequent full table scans, then you will see some performance gains. In addition to this, you will need memory to go along with additional CPU, otherwise performance will not improve as much as expected.
3. Yes, hints can force parallel query.

Barbara Kennedy wrote:

> The parallellization is only beneficial if you are querying large result
> sets. If you are looking up a row in a table by the primary key then you
> would gain no benefit from parallellization.
> <gdas_at_my-deja.com> wrote in message news:8pjck2$4qh$1_at_nnrp1.deja.com...
> > Hi, I apologize if these questions seem basic...
> >
> > We currently have an Oracle test/development database running on a
> > single processor Windows NT Server. We have a new machine coming soon
> > which is a dual processor NT box, but is expandable to up to 4 CPUs. I
> > am hoping to move the database to this new machine and I am trying to
> > assess what I will need to do in order for oracle to take advantage of
> > the additional processor. I have 3 specific questions:
> >
> > 1. Will I need to change/set any of the init.ora parameters?
> > 2. Currently none of my tables were created using any specified degree
> > of parallelism. If I migrate the data to the new instance as is
> > (without any degree of parallelism) and don't change the application
> > code at all to send parallel hints, will I still see some benefit from
> > the additional processor?
> > 3. Can I use parallel hints in SQL, even if the underlying tables were
> > not created with any parallel clause?
> >
> > Thanks in advance for any tips,
> >
> > Gavin
> >
> >
> > Sent via Deja.com http://www.deja.com/
> > Before you buy.
Received on Tue Sep 12 2000 - 01:23:47 CDT