1. Database Reference
  2. Dynamic Performance Views
  3. Dynamic Performance (V$) Views: V$IM_COLUMN_LEVEL to V$RULE_SET_AGGREGATE_STATS
  4. V$LIBCACHE_LOCKS

8.34 V$LIBCACHE_LOCKS

V$LIBCACHE_LOCKS displays information about the library cache locks and pins. Locks and pins are distinguished based on the value of the TYPE column.

Column Datatype Description

TYPE

VARCHAR2(4)

LOCK or PIN

ADDR

RAW(4 | 8)

Address of the lock/pin

HOLDING_USER_SESSION

RAW(4 | 8)

User session holding this lock/pin

HOLDING_SESSION

RAW(4 | 8)

Session holding this lock/pin

OBJECT_HANDLE

RAW(4 | 8)

Handle address for which the lock/pin is acquired

LOCK_HELD

RAW(4 | 8)

If the type is LOCK, then LOCK_HELD represents the pin that is pinning the object.

If the type is PIN, then LOCK_HELD represents the lock that is locking the object.

REFCOUNT

NUMBER

Reference count for this lock/pin

MODE_HELD

NUMBER

Lock/pin mode held:

  • 0 - No lock/pin held

  • 1 - Null mode

  • 2 - Share mode

  • 3 - Exclusive mode

MODE_REQUESTED

NUMBER

Lock/pin mode requested:

  • 0 - No lock/pin requested

  • 1 - Null mode

  • 2 - Share mode

  • 3 - Exclusive mode

SAVEPOINT_NUMBER

NUMBER

Kernel transaction savepoint number at the time the lock/pin was acquired

CON_ID

NUMBER

The ID of the container to which the data pertains. Possible values include:

  • 0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.

  • 1: This value is used for rows containing data that pertain to only the root

  • n: Where n is the applicable container ID for the rows containing data