Re: parallel query
Date: 1996/10/10
Message-ID: <NEWTNews.845016912.3493.dafis_at_ppp.test.jccbi.gov>#1/1
In article <325ca6a2.2452126_at_n5.gbso.net>, <chuckh_at_dvol.com> writes:
> From: chuckh_at_dvol.com (Chuck Hamilton)
> Newsgroups: comp.databases.oracle
> Subject: parallel query
> Date: Wed, 09 Oct 1996 13:24:13 GMT
> Organization: Do I look organized to you?
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> I've noticed that even though I don't have an SMP system, if I turn on
> parallel query most of my queries complete about 30% faster.
>
> I've also noticed that in addition to the p_000n background processes
> PQ creates, I also sometimes get additional sessions showing up in
> v$sessions view. What are these sessions and do they count towards my
> licensed users limit? I didn't see anything in the documentation about
> them.
> --
> Chuck Hamilton
> chuckh_at_dvol.com
>
> This message delivered by electronic sled dogs. WOOF!
>
No they are concidered one session to you licencing parameters. These are
just the processes spawned by your quiry. Your processor can work alot faster
than your disks can push data out. As long as you have more than one storage
device for your tablespace your indexes and quiries should work faster. You
can set your degree of parallelism equal to the number of devices on your
tablespace. That should be a good rule. Just be careful not to globally set
all your objects with the same degree of parallelism. It should be set
according to your # of devices associated with that object/tablespace. More
than one process to a device could actually degrade performance.
Martin Douglas Received on Thu Oct 10 1996 - 00:00:00 CEST