Re: Parallel Server and Parallel Query

In article <331dfcca.17273582_at_WEIPROXY>, <djetz_at_sierrasys.com> wrote:
>First Question:
>
>When Oracle does a parallel query operation, how does it determine how
>to divide up the data between the query processors? Data location,
>data values? What?

Depends on platform (SMP, MPP) and version.

>Second Question:
>
>When using parallel server option, you must use raw devices. You
>create a logical volume on one physical disk or across many physical
>disks. If you create a lv across many physical disks and use this lv
>as the datafile when creating the tablespace, does Oracle know how
>many physical disks the tablespace spans? If it does, then how does
>it know?

Parallel Server Option is for MPP and clusters is this what you are running? Logical Volume Manager is suposed to hide the physical layout from the applications.

>I ask this question because we are using the parallel server option
>and are considering using parallel query on some of our SQL. If
>Oracle can't detect the physical disks in a tablespace, then it might
>not be a good idea to use parallel query because it is really
>important to know where your data is sitting. Does anyone have
>experience with this?

If you are running a cluster/MPP environment then some platforms are/will support function shipping.

>Second Question, part 2:
>
>Has anyone done any Oracle striping on a raw device before? I know
>that this could be very expensive (disk-wise), but we may need to do
>it anyway. I would appreciate any comments on how you did this and
>any other experience you had with this.
>
>I can receive e-mail and read this newsgroup, but I can't e-mail out
>from this site so I thank anyone in advance for any information they
>submit.
>
>Doris Jetz
>Consultant.

More information on the configuration and the goal would be useful

mjr Received on Thu Mar 06 1997 - 00:00:00 CST