Re: Oracle parallel server, Sequence SYS.DBMS_LOCK_ID

Hi,

Many locks means that your data updated.

The high network traffic means that the database blocks that updated by one node required by other node also for update.

N.B. parallel server good for fault-tolerant purposes and for query.

Please check - how many PQO servers simultaneousy work, PQO hits, etc.

Also note that Oracle change method of locks for Parallel Server in version 8i, so if you upgrade to the version 8i many problems with the locks in the Parallel Server will be relovle.

Best regards,
 Vladimir

In article <927228430.12368.1.nnrp-07.9e984b29_at_news.demon.co.uk>,   "Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote:
>
> I'm not 100% sure about this, but I believe the DBMS_LOCK_ID
> sequence is only used in the DBMS_LOCK package for generating
> meaningless lock IDs when the application wants to define an
> end-user lock.
>
> As such it should be safe to increase the cache size on it
> without causing problems.
>
> However, has some application developer fiddled with it in
> some way for application purposes. OPS can introduce
> problems with sequences, because if they are defined as
> ORDERed (which this one should not be) or NOCACHE
> then you get a lot of pinging on the SEQ$ block (and its
> hash partners).
>
> --
>
> Jonathan Lewis
> Yet another Oracle-related web site: www.jlcomp.demon.co.uk
>
> Stojentin, Fred wrote in message <37445732.5F7314A9_at_orgdv.din.de>...
> >Hello,
> >
> > I am observing very high network traffic between the nodes of the
ops
> >cluster under some
> > circumstances. The nodes generate a good amount of traffic because
they
> >all want to access the
> > table seq$ (nearly all 10-20ms).
> >
> > A closer look at the sequences show that all application sequences
are
> >fine, but there is a system
> > sequence with a high increasing rate. This sequence is
> >SYS.DBMS_LOCK_ID. The default chache
> > value for this sequence seems to be very low.
> >
> > Is it possible and save to increase the cache (default 20) for the
> >sequence SYS.DBMS_LOCK_ID or
> >are there some internals which depends on the default cache value?
> >
> > Thanks in Advance
> > Fred Stojentin
> >
>
>

--== Sent via Deja.com http://www.deja.com/ ==-- ---Share what you know. Learn what you don't.--- Received on Fri May 21 1999 - 04:09:54 CDT