V$LOCK

This view lists the locks held by the database.

Fields

The most relevant view fields are:

• SID: An identifier for the session holding or acquiring the lock

• ID1: Lock identifier #1 (depends on TYPE)

• ID2: Lock identifier #2 (depends on TYPE)

• TYPE: The type of lock; user locks can be TM (DML enqueue), TX (transaction enqueue), or UL (user supplied)

• LMODE: A lock mode in which the session holds the lock; values can be:

  • NONE

  • NULL (NULL)

  • ROW-S (SS)

  • ROW-X

  • SHARE (S)

  • S/ROW-X (SSX)

  • EXCLUSIVE (X)

• REQUEST: A lock mode in which the process request locks; values are the same as for the LMODE field

• CTIME: The time since current mode was granted

• BLOCK: If the lock is blocking another lock the value is 1, otherwise the value is 0

See also

• The DBA_BLOCKERS, DBA_WAITERS, V$ENQUEUE_LOCK, and V$LOCKED_OBJECT sections in this appendix