I was going to write up a post about researching library cache pin locks, but someone else has done a very thorough job already: https://orainternals.wordpress.com/2009/06/02/library-cache-lock-and-library-cache-pin-waits/. Especially useful is this query: select distinct ses.ksusenum sid, ses.ksuseser serial#, ses.ksuudlna username,ses.ksuseunm machine, ob.kglnaown obj_owner, ob.kglnaobj obj_name ,pn.kglpncnt pin_cnt, pn.kglpnmod pin_mode, pn.kglpnreq pin_req , w.state, w.event, w.wait_Time, w.seconds_in_Wait from […]