Definition:

Individual Waits:

  Parameters:

  Wait Time:

The waiter waits up to 3 seconds (1 second if PMON) for the PIN to become available. If not available then the session waits again, incrementing SEQ# in <> .

  Finding Blockers:

The following SQL can be used to show the sessions which are holding and/or requesting pins on the object that given in P1 in the wait:

  SELECT s.sid, kglpnmod "Mode", kglpnreq "Req"
    FROM x$kglpn p, v$session s
   WHERE p.kglpnuse=s.saddr
     AND kglpnhdl='&P1RAW'
  ;

An X request (3) will be blocked by any pins held S mode (2) on the object.
An S request (2) will be blocked by any X mode (3) pin held, or may queue behind some other X request.

Diagnosis of why there is a blocking scenario will usually need help from Oracle support. If you just want to clear the immediate issue then the SID information above should allow you to kill off any blocking sessions. Proper diagnosis will usually require you to collect 3 SYSTEMSTATE and/or HANGANALYZE dumps at 30 seconds intervals then submit these to Oracle support with full details of the sessions and objects involved. To take a SYSTEMSTATE or HANGANALYZE dump connect to the instance as a user with ALTER SYSTEM privilege and issue the command:

  ALTER SESSION SET max_dump_file_size = UNLIMITED;
  ALTER SYSTEM SET EVENTS 'immediate trace name systemstate level 266';

This will produce a trace file under the DIAGNOSTIC_DEST in 11g, or in the USER_DUMP_DEST in earlier releases (or BACKGROUND_DUMP_DEST if connected to a shared server).
In a Parallel Server or RAC environments SYSTEMSTATE dumps should be taken 3 times on each node.

Systemwide Waits:

Reducing Waits / Wait times:

You can restrict the list below to issues likely to affect one of the following versions by clicking the relevant button: 
           

NB	Bug	Fixed	Description
	12411746	12.1.0.0	RAC waits for "library cache pin" do not time out (do not trigger ORA-4021)
	10138929	11.2.0.3, 12.1.0.0	ORA-600 [17069] in replication receiver / self deadlock on replication internal package
	9327929	11.2.0.2	ORA-600 [kglLockOwnersListDelete] / DIRECTORY object waits using EXTERNAL tables
	6618312	11.1.0.7, 11.2.0.1	Deadlock between ON COMMIT materialized view refresh and query rewrite (library cache pin V lock deadlock)
	6475688	11.1.0.7, 11.2.0.1	Concurrent rewrite and on-commit refresh can deadlock (library cache pin <--> lock)
	6644122	10.2.0.5, 11.1.0.7	ON COMMIT refresh deadlock (library cache pin V lock)
	5604698	10.2.0.4, 11.1.0.6	Deadlock between 'library cache lock' and 'library cache pin' using replication
	7226463	10.2.0.5	EXECUTE IMMEDIATE no releasing mutex or library cache pin
	3717619	9.2.0.6, 10.1.0.4, 10.2.0.1	Deadlock/hang possible due to concurrent cursor loads referencing same INVALID trigger
	3605165	9.2.0.6, 10.1.0.4, 10.2.0.1	Hang/deadlock between sessions concurrently loading a cursor with INVALID trigger
	3374640	10.1.0.3, 10.2.0.1	Create local partitioned domain index can hang
	3253770	9.2.0.6, 10.1.0.3, 10.2.0.1	ORA-4021 / "library cache pin" waits on RAC executing Java stored procedures
+	2968709	9.2.0.5, 10.1.0.2	High "library cache pin" waits possible
	3371003	9.2.0.6	Logical standby apply hang (library cache pin waits)
	3352902	9.2.0.6	Logical apply may hang (library cache pin)

• '*' against a bug indicates that an alert exists for that issue.
• '+' indicates a particularly notable bug.
• 'P' indicates a port specific bug.
• "OERI:nnnnn" is used as shorthand for ORA-600 [nnnnn].

Related: