First, login using the -prelim option of SQL*Plus as "/ as sysdba".
Then run the following:
alter session set tracefile_identifier='sysstatedump'; oradebug setmypid oradebug unlimit prompt Issuing command: oradebug -g all dump systemstate 10 oradebug -g all dump systemstate 10 prompt Sleeping for 1 minute !sleep 60 oradebug -g all dump systemstate 10 prompt We may not be able to do dump of locks prompt Issuing command: oradebug -g all dump locks 8 prompt If the sqlplus session hangs here for more than several minutes prompt kill it by hitting control-c oradebug -g all dump locks 8 prompt Sleeping for 1 minute !sleep 60 oradebug -g all dump locks 8
Posted by Charles Kim, Oracle ACE