V$LOCKED_OBJECT

V$LOCKED_OBJECT lists all locks acquired by every transaction on the system. It shows which sessions are holding DML locks (that is, TM-type enqueues) on what objects and in what mode.

Column	Datatype	Description
`XIDUSN`	`NUMBER`	Undo segment number
`XIDSLOT`	`NUMBER`	Slot number
`XIDSQN`	`NUMBER`	Sequence number
`OBJECT_ID`	`NUMBER`	Object ID being locked
`SESSION_ID`	`NUMBER`	Session ID
`ORACLE_USERNAME`	`VARCHAR2(30)`	Oracle user name
`OS_USER_NAME`	`VARCHAR2(30)`	OS user name
`PROCESS`	`VARCHAR2(12)`	OS process ID
`LOCKED_MODE`	`NUMBER`	Lock mode