|Oracle® Database Reference
12c Release 1 (12.1)
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This appendix lists Oracle enqueues. Enqueues are shared memory structures (locks) that serialize access to database resources. They can be associated with a session or transaction. Enqueue names are displayed in the
LOCK_TYPE column of the
DBA_LOCK_INTERNAL data dictionary views.
A resource uniquely identifies an object that can be locked by different sessions within an instance (local resource) or between instances (global resource). Each session that tries to lock the resource will have an enqueue on the resource.
Note:The names of enqueues and their definitions may change from release to release.
The Oracle enqueues are:
FP, File Object
KP, contention in Oracle Data Pump startup and shutdown processes
KO, Multiple Object Checkpoint
ZA, Exclusive Lock When Moving Audit Table