Re: Row cache lock wait issue in RAC

Looks like an SR is your only way out for now ...

cheers
anand

On 01/06/06, Luca Canali <Luca.Canali_at_cern.ch> wrote:
>
> Hi Anand,
>
> I am using Oracle 10.2.0.2 with RAC (6 nodes ) + ASM on RHEL 3. I use LMT
> bigfile tablespaces and ASSM. I am aware of the exchange partition bug, but
> my case looks different: I don't seem to have any deadlocks and using the
> workaround you mention (fixed quotas) did not help.
>
> Cheers,
> L.
>
>
> ------------------------------
> *From:* Anand Rao [mailto:panandrao_at_gmail.com]
> *Sent:* Thursday, June 01, 2006 11:15 AM
>
> *To:* Luca Canali
> *Cc:* oracle-l_at_freelists.org
> *Subject:* Re: Row cache lock wait issue in RAC
>
> Luca,
>
> In LMT, Oracle acquired a row cache enqueue on dc_tablespace_quotas after
> a segment is built. this could even be a partition exchange or add. In DMT,
> it used to be worse, where Oracle acquired this enqueue to check quotas and
> add extents.
>
> The quota checks are still performed but only at the end, even though you
> may have provided unlimited quota. i think Dimitre's suggestion to provide
> fixed quota came from this aspect. so, we both assume you are using LMT :)
>
> also, are you using partitions and dynamically exchanging data to
> partitions? if so, run the EXCHANGE PARTITION statements serially and ensure
> it involves a single tablespace.
>
> one bug hit suggested providing the quotas in M or K instead of bytes,
> especially if the quota is more than 4GB.
>
> unfortunately, you are hitting a couple of bugs related to this enqueue
> especially while Oracle updates TSQ$ table...problem occuring mainly in high
> insert RAC environments.
>
> you didn't mention the version. depending on yours, you can get a backport
> fix. some fixes are available in 10.1...but there are a couple of bugs in
> 10.1 too :(
>
> hope that helps
>
> cheers
> anand
>
> On 01/06/06, Radoulov, Dimitre <cichomitiko_at_gmail.com> wrote:
> >
> > > By the way, I would be quite interested to know why oracle needs to
> > > acquire row cache lock on dc_tablespace_quotas in this case and if
> > there
> > > is any way to skip this operation with 'a clever hack'.
> >
> > If you search on MetaLink with keyword "dc_tablespace_quotas" (with bug
> > database search enabled), there are a few bugs related to data
> > dictionary
> > cache deadlocks.
> >
> >
> > Regards
> > Dimitre
> >
> > --
> > http://www.freelists.org/webpage/oracle-l
> >
> >
> >
>

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