Contention for undo segments

I'm posting this question for our DBAs.

Oracle 9.2.0.5 RAC:
Oracle9i Enterprise Edition Release 9.2.0.5.0 - 64bit Production PL/SQL Release 9.2.0.5.0 - Production
CORE 9.2.0.6.0 Production
TNS for Solaris: Version 9.2.0.5.0 - Production NLSRTL Version 9.2.0.5.0 - Production

We have a batch processing environment that is undergoing very high insert/update/delete activity on a regular basis.

Today we are suddenly experiencing severe contention for undo segment headers. The SQL in question has not changed recently. Today's problems were preceded by two full days of excellent performance and the instances were not shut down inbetween (nor were there any parameter changes).

As we wait for feedback from Oracle Support, we are trying to find the session that is at the head of the logjam. The reason code on which these processes are hanging is 130 (P3=130, buffer busy global CR request). Our question is, how do you translate the V$LOCK_ELEMENT.LOCK_ELEMENT_NAME to a an actual resource and a SID?

(If you have any ideas for us, please cc: sbala_at_Newgen.com if you don't mind. Thank you!)

Tim Hall

--
http://www.freelists.org/webpage/oracle-l