UL stands for ‘User-defined Lock’. Obviously some of your sessions are waiting because of user locks. See DBMS_LOCK package.

Regards, Joze

Does anyone know what the wait event named “enq: UL – contention” means?  There is nothing in Metalink or anywhere that I can find that gives the definition.  I have a session that waits more than 90% of its time on this event.

Thanks.