Re: Oracle recommends rebuilding IOTs in AQ to reduce redo
Date: Mon, 7 Jan 2008 07:41:26 +0000
It's interesting to me that a coalesce is what is happening for multiple subscriber queues, but not single and that there is a compatible check as well. It rather suggests to me that some thought has gone into the procedure - perhaps as a result of relevant bugs.
On 07/01/2008, Greg Rahn <greg_at_structureddata.org> wrote:
> The coalesce would be a better option IMO (I've personally used this
> as a recommendation from the AQ dev team) and it can be done while the
> workload is in progress, while a rebuild requires the queues to be
> Another recommendation I received is *not* to use ASSM tablespaces for
> the queues.
> What db version is this?
> What is the queue navigation type (first or next message)?
> Are you doing single row or array enqueues/dequeues?
> On 1/6/08, Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk> wrote:
> > In simple indexes, the optimum solution to this type of problem
> > is usually a coalesce, rather than a rebuild. Given that Queues
> > are IOTs that you're not really supposed to know about, it's
> > not too surprising that Oracle has suggested a rebuild instead.
> Greg Rahn
-- Niall Litchfield Oracle DBA http://www.orawin.info -- http://www.freelists.org/webpage/oracle-lReceived on Mon Jan 07 2008 - 01:41:26 CST