Re: Oracle RAC Stored Procedure scalability

From: DA Morgan <damorgan_at_psoug.org>
Date: Thu, 03 Aug 2006 10:26:48 -0700
Message-ID: <1154626009.326275@bubbleator.drizzle.com>

Serge Rielau wrote:

> HansF wrote:


>>> The different members of the cluster all access the same disk.  So if 

>>> the

>>> sql statements can scale horizontillay then the stored proc can
>>> Jim
>>
>> In support of that, if the SQL statement can take advantage of
>> parallelism
>> on an SMP box, it can also take advantage of RAC.
>>
>> The network traffic concern is somewhat valid until you realize that a
>> separate network (including separate network cards) is needed for RAC
>> interconnect purposes anyway.
>>
>> The question implies some holes in basic understanding of RAC
>> architecture. As that is too large a topic to review in a newsgroup,
>> I'd suggest it's time to hit the RAC concepts books (again).

> Actually I don't think the poster is asking a bad question here.
> Procedures are in their very nature procedural. That means that by 
> default statements are to execute in a specific order. Hence the 
> procedural logic is, by default, a serialization point.
> Each SQL statement can parallelize, but the logic itself cannot.

With Oracle that is not necessarily true. One can go from synchronous to asynchronous by leveraging AQ. One could kick of multiple threads and then merge a result set.

I'm not advocating it as a winning strategy in most situations ... but it can be done and I can conceive of situations where it might be part of a solution.

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace x with u to respond)
Puget Sound Oracle Users Group
www.psoug.org

Received on Thu Aug 03 2006 - 12:26:48 CDT