We've got a situation where we have sessions experiencing "enq: TX - row
lock contention" with no blocking session.
GV$SESSION.BLOCKING_SESSION is null
DBA_WAITERS is empty
DBA_BLOCKERS is empty
I've gotten around this by joining gv$locked_object to gv$session where
session.wait_class='Idle' and wait_time_micro/1000000 > 120 (seconds).
Some of the locks are for sessions with thousands of wait seconds waiting
on sqlnet.
*BUT* the issue is, why isn't oracle able to find the blocking sessions?
How can I dump/trace the blocking session manually?
In Grid Control we see stuff like: "lock deadlock retry" in the wait events
for the sessions waiting on "enq: TX - row lock".
In the session trace files, we see stuff like "unable to determine final
blocker" .
Any thoughts?
Chris
