Re: Very poor read performance, query independent

Scott,

The temp tablespace is on a disk of his own.
Thanks!

Charles

On Sat, Jul 15, 2017 at 7:58 PM, Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com>
wrote:

> On Sat, Jul 15, 2017 at 11:53 AM, Charles Nadeau
> <charles(dot)nadeau(at)gmail(dot)com> wrote:
> > Mark,
> >
> > I increased the read ahead to 16384 and it doesn't improve performance.
> My
> > RAID 0 use a stripe size of 256k, the maximum size supported by the
> > controller.
>
> Are your queries still spilling to disk for sorts? If this is the
> case, and they're just too big to fit in memory, then you need to move
> your temp space, where sorts happen, onto another disk array that
> isn't your poor overworked raid-10 array. Contention between sorts and
> reads can kill performance quick, esp on spinning rust.
>

--
Charles Nadeau Ph.D.
http://charlesnadeau.blogspot.com/