On Thu, Oct 16, 2003 at 12:49:41PM -0400, Tbird67ForSale@stripped wrote:
> In a message dated 10/16/03 9:27:04 AM Eastern Daylight Time,
> sgreen@stripped writes:
>
> > This is down to the OS. As MySQL is multy threaded its all down to SMP
> > support.
> >
>
> with all due respect, I don't think that is 100% true. Although
> certainly the underlying OS kernel must support multi-processors and
> discrete processor selection functionality, I am looking for
> user-based control of query execution. That would have to come from
> the DB package. Oracle has such functionality (at least on
> Unix-based versions) that I've used recently, including the ability
> to dynamically allocate more processors to a running query. We do
> this all the time to complete a task of higher priority than others.
> Certainly with Oracle one pays dearly for such software. I am just
> wondering what options are available in MySQL (if any).
MySQL offers no control over how many processors a giver query will
use because each query can use only a single processor at a time.
There's a 1-to-1 mapping from queries to threads in MySQL. Each
thread may execute on only one CPU.
Jeremy
--
Jeremy D. Zawodny | Perl, Web, MySQL, Linux Magazine, Yahoo!
<Jeremy@stripped> | http://jeremy.zawodny.com/
MySQL 4.0.15-Yahoo-SMP: up 32 days, processed 1,221,267,552 queries (431/sec. avg)
