Re: Oracle parallel server, Sequence SYS.DBMS_LOCK_ID

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
>
Received on Thu May 20 1999 - 14:22:26 CDT