On 5 Mai, 20:28, Wayne Happ <wayneh...@earthlink.net> wrote:
> I'm working in a large corporate data center with a typical EMC (Like)
> data storage array. I don't know exactly what it is... But it's some
> sort of storage system. I have a co-worker who is convinved that
> performance can be improved by specifying what segments to place the
> database on. An active database gets it's own disk and so on.
> Now I've been at this for a while and I know that this sort of
> optimization was done in the past. But when I have an SQL server
> connected to one of the modern storage devices, is the concept of
> segments and disks relevant anymore? I know there are segments defined
> on my dataserver. But as far as I know, that's an abstraction to humor
> me. My hardware huy tells me that these devices have something of
> their own OS and one never really knows how it's deciding to store
> data. Let alone where exactly.
>
> Am I more wrong then right or visa-versa?
>
> Wayne

Hi Wayne,
i am running big, timecritical oltp and olap produktion since many
years.
Over the years the storage became more an more intelligent from disks
over stripes
with own caches to intelligent, capsulated storage-centers. One thing
i still do is:
Im still using in minimum 2 segments for data to split tables and
their indexes
and sent them to (depending of storagesystems)
different disks or different stripes or different storage-boxes (-
systems) to
avoid concurrency when accessing data by index.
Im using this simple logic over cross,
so table 1-data is seg1, its indexes on seg2 , table 2 is seg2, its
indexes on seg 1and so on.
So thats the rest (beside important questions of data security for
data location/logs and so on ) of my policy
with modern storage-systems and ase.
Regards,
Karl