Enqueue Wait events and their descriptions in Oracle Database 10g

Enqueue waits events usually causes problems in busy Oracle databases. But oracle online document only have some of them until 11gR2, not sure why. 


In Oracle Database 10g Release 1, each enqueue type is represented by its own wait event, making it much easier to understand exactly what type of enqueue the session is waiting for. You do not need to decipher the values from the P1, P2, P3, P1RAW, P2RAW, and P3RAW columns in the V$SESSION_WAIT or the V$SESSION view.

The following table lists all the enqueue waits in Oracle Database 10g Release 1 and describes what the enqueue is for. This information is available in the X$KSQST structure. The aggregated statistics for each of these enqueue types is displayed by the view V$ENQUEUE_STAT.

types is displayed by the view V$ENQUEUE_STAT.

Enqueue Type	Description
enq: AD – allocate AU	Synchronizes accesses to a specific OSM (Oracle Software Manager) disk AU
enq: AD – deallocate AU	Synchronizes accesses to a specific OSM disk AU
enq: AF – task serialization	Serializes access to an advisor task
enq: AG – contention	Synchronizes generation use of a particular workspace
enq: AO – contention	Synchronizes access to objects and scalar variables
enq: AS – contention	Synchronizes new service activation
enq: AT – contention	Serializes alter tablespace operations
enq: AW – AW$ table lock	Allows global access synchronization to the AW$ table (analytical workplace tables used in OLAP option)
enq: AW – AW generation lock	Gives in-use generation state for a particular workspace
enq: AW – user access for AW	Synchronizes user accesses to a particular workspace
enq: AW – AW state lock	Row lock synchronization for the AW$ table
enq: BR – file shrink	Lock held to prevent file from decreasing in physical size during RMAN backup
enq: BR – proxy-copy	Lock held to allow cleanup from backup mode during an RMAN proxy-copy backup
enq: CF – contention	Synchronizes accesses to the controlfile
enq: CI – contention	Coordinates cross-instance function invocations
enq: CL – drop label	Synchronizes accesses to label cache when dropping a label
enq: CL – compare labels	Synchronizes accesses to label cache for label comparison
enq: CM – gate	Serializes access to instance enqueue
enq: CM – instance	Indicates OSM disk group is mounted
enq: CT – global space management	Lock held during change tracking space management operations that affect the entire change tracking file
enq: CT – state	Lock held while enabling or disabling change tracking to ensure that it is enabled or disabled by only one user at a time
enq: CT – state change gate 2	Lock held while enabling or disabling change tracking in RAC
enq: CT – reading	Lock held to ensure that change tracking data remains in existence until a reader is done with it
enq: CT – CTWR process start/stop	Lock held to ensure that only one CTWR (Change Tracking Writer, which tracks block changes and is initiated by the alter database enable block change tracking command) process is started in a single instance
enq: CT – state change gate 1	Lock held while enabling or disabling change tracking in RAC
enq: CT – change stream ownership	Lock held by one instance while change tracking is enabled to guarantee access to thread-specific resources
enq: CT – local space management	Lock held during change tracking space management operations that affect just the data for one thread
enq: CU – contention	Recovers cursors in case of death while compiling
enq: DB – contention	Synchronizes modification of database wide supplemental logging attributes
enq: DD – contention	Synchronizes local accesses to ASM (Automatic Storage Management) disk groups
enq: DF – contention	Enqueue held by foreground or DBWR when a datafile is brought online in RAC
enq: DG – contention	Synchronizes accesses to ASM disk groups
enq: DL – contention	Lock to prevent index DDL during direct load
enq: DM – contention	Enqueue held by foreground or DBWR to synchronize database mount/open with other operations
enq: DN – contention	Serializes group number generations
enq: DP – contention	Synchronizes access to LDAP parameters
enq: DR – contention	Serializes the active distributed recovery operation
enq: DS – contention	Prevents a database suspend during LMON reconfiguration
enq: DT – contention	Serializes changing the default temporary table space and user creation
enq: DV – contention	Synchronizes access to lower-version Diana (PL/SQL intermediate representation)
enq: DX – contention	Serializes tightly coupled distributed transaction branches
enq: FA – access file	Synchronizes accesses to open ASM files
enq: FB – contention	Ensures that only one process can format data blocks in auto segment space managed tablespaces
enq: FC – open an ACD thread	LGWR opens an ACD thread
enq: FC – recover an ACD thread	SMON recovers an ACD thread
enq: FD – Marker generation	Synchronization
enq: FD – Flashback coordinator	Synchronization
enq: FD – Tablespace flashback on/off	Synchronization
enq: FD – Flashback on/off	Synchronization
Enqueue Type	Description
enq: FG – serialize ACD relocate	Only 1 process in the cluster may do ACD relocation in a disk group
enq: FG – LGWR redo generation enq race	Resolves race condition to acquire Disk Group Redo Generation Enqueue
enq: FG – FG redo generation enq race	Resolves race condition to acquire Disk Group Redo Generation Enqueue
enq: FL – Flashback database log	Synchronizes access to Flashback database log
enq: FL – Flashback db command	Synchronizes Flashback Database and deletion of flashback logs
enq: FM – contention	Synchronizes access to global file mapping state
enq: FR – contention	Begins recovery of disk group
enq: FS – contention	Synchronizes recovery and file operations or synchronizes dictionary check
enq: FT – allow LGWR writes	Allows LGWR to generate redo in this thread
enq: FT – disable LGWR writes	Prevents LGWR from generating redo in this thread
enq: FU – contention	Serializes the capture of the DB feature, usage, and high watermark statistics
enq: HD – contention	Serializes accesses to ASM SGA data structures
enq: HP – contention	Synchronizes accesses to queue pages
enq: HQ – contention	Synchronizes the creation of new queue IDs
enq: HV – contention	Lock used to broker the high watermark during parallel inserts
enq: HW – contention	Lock used to broker the high watermark during parallel inserts
enq: IA – contention	Information not available
enq: ID – contention	Lock held to prevent other processes from performing controlfile transaction while NID is running
enq: IL – contention	Synchronizes accesses to internal label data structures
Enqueue Type	Description
enq: IM – contention for blr	Serializes block recovery for IMU txn
enq: IR – contention	Synchronizes instance recovery
enq: IR – contention2	Synchronizes parallel instance recovery and shutdown immediate
enq: IS – contention	Synchronizes instance state changes
enq: IT – contention	Synchronizes accesses to a temp object’s metadata
enq: JD – contention	Synchronizes dates between job queue coordinator and slave processes
enq: JI – contention	Lock held during materialized view operations (such as refresh, alter) to prevent concurrent operations on the same materialized view
enq: JQ – contention	Lock to prevent multiple instances from running a single job
enq: JS – contention	Synchronizes accesses to the job cache
enq: JS – coord post lock	Lock for coordinator posting
enq: JS – global wdw lock	Lock acquired when doing wdw ddl
enq: JS – job chain evaluate lock	Lock when job chain evaluated for steps to create
enq: JS – q mem clnup lck	Lock obtained when cleaning up q memory
enq: JS – slave enq get lock2	Gets run info locks before slv objget
enq: JS – slave enq get lock1	Slave locks exec pre to sess strt
enq: JS – running job cnt lock3	Lock to set running job count epost
enq: JS – running job cnt lock2	Lock to set running job count epre
enq: JS – running job cnt lock	Lock to get running job count
enq: JS – coord rcv lock	Lock when coord receives msg
enq: JS – queue lock	Lock on internal scheduler queue
enq: JS – job run lock – synchronize	Lock to prevent job from running elsewhere
enq: JS – job recov lock	Lock to recover jobs running on crashed RAC inst
Enqueue Type	Description
enq: KK – context	Lock held by open redo thread, used by other instances to force a log switch
enq: KM – contention	Synchronizes various Resource Manager operations
enq: KP – contention	Synchronizes kupp process startup
enq: KT – contention	Synchronizes accesses to the current Resource Manager plan
enq: MD – contention	Lock held during materialized view log DDL statements
enq: MH – contention	Lock used for recovery when setting Mail Host for AQ e-mail notifications
enq: ML – contention	Lock used for recovery when setting Mail Port for AQ e-mail notifications
enq: MN – contention	Synchronizes updates to the LogMiner dictionary and prevents multiple instances from preparing the same LogMiner session
enq: MR – contention	Lock used to coordinate media recovery with other uses of datafiles
enq: MS – contention	Lock held during materialized view refresh to set up MV log
enq: MW – contention	Serializes the calibration of the manageability schedules with the Maintenance Window
enq: OC – contention	Synchronizes write accesses to the outline cache
enq: OL – contention	Synchronizes accesses to a particular outline name
enq: OQ – xsoqhiAlloc	Synchronizes access to olapi history allocation
enq: OQ – xsoqhiClose	Synchronizes access to olapi history closing
enq: OQ – xsoqhistrecb	Synchronizes access to olapi history globals
enq: OQ – xsoqhiFlush	Synchronizes access to olapi history flushing
enq: OQ – xsoq*histrecb	Synchronizes access to olapi history parameter CB
enq: PD – contention	Prevents others from updating the same property
enq: PE – contention	Synchronizes system parameter updates
Enqueue Type	Description
enq: PF – contention	Synchronizes accesses to the password file
enq: PG – contention	Synchronizes global system parameter updates
enq: PH – contention	Lock used for recovery when setting proxy for AQ HTTP notifications
enq: PI – contention	Communicates remote Parallel Execution Server Process creation status
enq: PL – contention	Coordinates plug-in operation of transportable tablespaces
enq: PR – contention	Synchronizes process startup
enq: PS – contention	Parallel Execution Server Process reservation and synchronization
enq: PT – contention	Synchronizes access to ASM PST metadata
enq: PV – syncstart	Synchronizes slave start_shutdown
enq: PV – syncshut	Synchronizes instance shutdown_slvstart
enq: PW – prewarm status in dbw0	DBWR0 holds this enqueue indicating pre-warmed buffers present in cache
enq: PW – flush prewarm buffers	Direct Load needs to flush prewarmed buffers if DBWR0 holds this enqueue
enq: RB – contention	Serializes OSM rollback recovery operations
enq: RF – synch: per-SGA Broker metadata	Ensures r/w atomicity of DG configuration metadata per unique SGA
enq: RF – synchronization: critical ai	Synchronizes critical apply instance among primary instances
enq: RF – new AI	Synchronizes selection of the new apply instance
enq: RF – synchronization: chief	Anoints 1 instance’s DMON (Data Guard Broker Monitor) as chief to other instance’s DMONs
enq: RF – synchronization: HC master	Anoints 1 instance’s DMON as health check master
enq: RF – synchronization: aifo master	Synchronizes critical apply instance failure detection and failover operation
enq: RF – atomicity	Ensures atomicity of log transport setup
Enqueue Type	Description
enq: RN – contention	Coordinates nab computations of online logs during recovery
enq: RO – contention	Coordinates flushing of multiple objects
enq: RO – fast object reuse	Coordinates fast object reuse
enq: RP – contention	Enqueue held when resilvering is needed or when data block is repaired from mirror
enq: RS – file delete	Lock held to prevent file from accessing during space reclamation
enq: RS – persist alert level	Lock held to make alert level persistent
enq: RS – write alert level	Lock held to write alert level
enq: RS – read alert level	Lock held to read alert level
enq: RS – prevent aging list update	Lock held to prevent aging list update
enq: RS – record reuse	Lock held to prevent file from accessing while reusing circular record
enq: RS – prevent file delete	Lock held to prevent deleting file to reclaim space
enq: RT – contention	Thread locks held by LGWR, DBW0, and RVWR (Recovery Writer, used in Flashback Database operations) to indicate mounted or open status
enq: SB – contention	Synchronizes logical standby metadata operations
enq: SF – contention	Lock held for recovery when setting sender for AQ e-mail notifications
enq: SH – contention	Enqueue always acquired in no-wait mode; should seldom see this contention
enq: SI – contention	Prevents multiple streams table instantiations
enq: SK – contention	Serialize shrink of a segment
enq: SQ – contention	Lock to ensure that only one process can replenish the sequence cache
enq: SR – contention	Coordinates replication / streams operations
enq: SS – contention	Ensures that sort segments created during parallel DML operations aren’t prematurely cleaned up
Enqueue Type	Description
enq: ST – contention	Synchronizes space management activities in dictionary-managed tablespaces
enq: SU – contention	Serializes access to SaveUndo Segment
enq: SW – contention	Coordinates the ‘alter system suspend’ operation
enq: TA – contention	Serializes operations on undo segments and undo tablespaces
enq: TB – SQL Tuning Base Cache Update	Synchronizes writes to the SQL Tuning Base Existence Cache
enq: TB – SQL Tuning Base Cache Load	Synchronizes writes to the SQL Tuning Base Existence Cache
enq: TC – contention	Lock held to guarantee uniqueness of a tablespace checkpoint
enq: TC – contention2	Lock during setup of a unique tablespace checkpoint in null mode
enq: TD – KTF dump entries	KTF dumping time/scn mappings in SMON_SCN_TIME table
enq: TE – KTF broadcast	KTF broadcasting
enq: TF – contention	Serializes dropping of a temporary file
enq: TL – contention	Serializes threshold log table read and update
enq: TM – contention	Synchronizes accesses to an object
enq: TO – contention	Synchronizes DDL and DML operations on a temp object
enq: TQ – TM contention	TM access to the queue table
enq: TQ – DDL contention	DDL access to the queue table
enq: TQ – INI contention	TM access to the queue table
enq: TS – contention	Serializes accesses to temp segments
enq: TT – contention	Serializes DDL operations on tablespaces
enq: TW – contention	Lock held by one instance to wait for transactions on all instances to finish
Enqueue Type	Description
enq: TX – contention	Lock held by a transaction to allow other transactions to wait for it
enq: TX – row lock contention	Lock held on a particular row by a transaction to prevent other transactions from modifying it
enq: TX – allocate ITL entry	Allocating an ITL entry in order to begin a transaction
enq: TX – index contention	Lock held on an index during a split to prevent other operations on it
enq: UL – contention	Lock held used by user applications
enq: US – contention	Lock held to perform DDL on the undo segment
enq: WA – contention	Lock used for recovery when setting watermark for memory usage in AQ notifications
enq: WF – contention	Enqueue used to serialize the flushing of snapshots
enq: WL – contention	Coordinates access to redo log files and archive logs
enq: WP – contention	Enqueue to handle concurrency between purging and baselines
enq: XH – contention	Lock used for recovery when setting No Proxy Domains for AQ HTTP notifications
enq: XR – quiesce database	Lock held during database quiesce
enq: XR – database force logging	Lock held during database force logging mode
enq: XY – contention	Lock used by Oracle Corporation for internal testing

We can get the description of p1, p2 and p3 at v$event_name. You can also get them from p1text, p2text and p3text from v$session if the event is happening right now.

NAME	PARAMETER1	PARAMETER2	PARAMETER3
enq: AD – allocate AU	name|mode	group and disk number	AU number
enq: AD – deallocate AU	name|mode	group and disk number	AU number
enq: AF – task serialization	name|mode	task id	0
enq: AG – contention	name|mode	workspace #	generation
enq: AM – client registration	name|mode	id1	id2
enq: AM – rollback COD reservation	name|mode	id1	id2
enq: AM – shutdown	name|mode	id1	id2
enq: AO – contention	name|mode	workspace #	object #
enq: AS – modify service	name|mode	0	0
enq: AS – service activation	name|mode	0	0
enq: AT – contention	name|mode	0	0
enq: AU – audit index file	name|mode	XML audit index file	0
enq: AW – AW generation lock	name|mode	operation	workspace #
enq: AW – AW state lock	name|mode	operation	workspace #
enq: AW – AW$ table lock	name|mode	operation	workspace #
enq: AW – user access for AW	name|mode	operation	workspace #
enq: BF – PMON Join Filter cleanup	name|mode	node#/parallelizer#	bloom#
enq: BF – allocation contention	name|mode	node#/parallelizer#	bloom#
enq: BR – file shrink	name|mode	operation	file #
enq: BR – proxy-copy	name|mode	operation	file #
enq: CF – contention	name|mode	0	operation
enq: CI – contention	name|mode	opcode	type
enq: CL – compare labels	name|mode	object #	0
enq: CL – drop label	name|mode	object #	0
enq: CM – gate	name|mode	disk group #	type
enq: CM – instance	name|mode	disk group #	type
enq: CN – race with init	name|mode	reg id	0
enq: CN – race with reg	name|mode	reg id	0
enq: CN – race with txn	name|mode	reg id	0
enq: CT – CTWR process start/stop	name|mode	operation	operation parm
enq: CT – change stream ownership	name|mode	operation	operation parm
enq: CT – global space management	name|mode	operation	operation parm
enq: CT – local space management	name|mode	operation	operation parm
enq: CT – reading	name|mode	operation	operation parm
enq: CT – state	name|mode	operation	operation parm
enq: CT – state change gate 1	name|mode	operation	operation parm
enq: CT – state change gate 2	name|mode	operation	operation parm
enq: CU – contention	name|mode	handle	handle
enq: DB – contention	name|mode	EnqMode	0
enq: DD – contention	name|mode	disk group	type
enq: DF – contention	name|mode	0	file #
enq: DG – contention	name|mode	disk group	type
enq: DL – contention	name|mode	object #	0
enq: DM – contention	name|mode	type	type
enq: DN – contention	name|mode	0	0
enq: DP – contention	name|mode	0	0
enq: DR – contention	name|mode	0	0
enq: DS – contention	name|mode	0	0
enq: DT – contention	name|mode	0	0
enq: DV – contention	name|mode	object #	0
enq: DX – contention	name|mode	transaction entry #	0
enq: FA – access file	name|mode	disk group number	file number
enq: FB – contention	name|mode	tablespace #	dba
enq: FC – open an ACD thread	name|mode	disk group	thread
enq: FC – recover an ACD thread	name|mode	disk group	thread
enq: FD – Flashback coordinator	name|mode	Internal	Internal
enq: FD – Flashback on/off	name|mode	Internal	Internal
enq: FD – Marker generation	name|mode	Internal	Internal
enq: FD – Restore point create/drop	name|mode	Internal	Internal
enq: FD – Tablespace flashback on/off	name|mode	Internal	Internal
enq: FG – FG redo generation enq race	name|mode	disk group	type
enq: FG – LGWR redo generation enq race	name|mode	disk group	type
enq: FG – serialize ACD relocate	name|mode	disk group	type
enq: FL – Flashback database log	name|mode	Log #	zero
enq: FL – Flashback db command	name|mode	Log #	zero
enq: FM – contention	name|mode	0	0
enq: FP – global fob contention	name|mode	low file obj add	high file obj add
enq: FR – contention	name|mode	disk group	unused
enq: FS – contention	name|mode	0	type
enq: FT – allow LGWR writes	name|mode	disk group	thread
enq: FT – disable LGWR writes	name|mode	disk group	thread
enq: FU – contention	name|mode	0	0
enq: HD – contention	name|mode	disk group	0
enq: HP – contention	name|mode	tablespace #	dba
enq: HQ – contention	name|mode	object #	hash value
enq: HV – contention	name|mode	object #	0
enq: HW – contention	name|mode	table space #	block
enq: IA – contention	name|mode	0	0
enq: ID – contention	name|mode	0	0
enq: IL – contention	name|mode	object #	0
enq: IM – contention for blr	name|mode	pool #	0
enq: IR – contention	name|mode	0	0/1
enq: IR – contention2	name|mode	0	0/1
enq: IS – contention	name|mode	0	type
enq: IT – contention	name|mode	object #	0
enq: JD – contention	name|mode	0	0
enq: JI – contention	name|mode	view object #	0
enq: JQ – contention	name|mode	0	0
enq: JS – contention	name|mode	service ID	queue type
enq: JS – evt notify	name|mode	service ID	queue type
enq: JS – evtsub add	name|mode	service ID	queue type
enq: JS – evtsub drop	name|mode	service ID	queue type
enq: JS – job recov lock	name|mode	service ID	queue type
enq: JS – job run lock – synchronize	name|mode	service ID	queue type
enq: JS – q mem clnup lck	name|mode	service ID	queue type
enq: JS – queue lock	name|mode	service ID	queue type
enq: JS – sch locl enqs	name|mode	service ID	queue type
enq: JS – wdw op	name|mode	service ID	queue type
enq: KK – context	name|mode	0	redo thread
enq: KM – contention	name|mode	type	type
enq: KO – fast object checkpoint	name|mode	2	0
enq: KP – contention	name|mode	0	0
enq: KT – contention	name|mode	plan #	0
enq: MD – contention	name|mode	master object #	0
enq: MH – contention	name|mode	0	0
enq: MK – contention	name|mode	0	0
enq: ML – contention	name|mode	0	0
enq: MN – contention	name|mode	session ID	0
enq: MO – contention	name|mode	0	0
enq: MR – contention	name|mode	0 or file #	type
enq: MS – contention	name|mode	master object #	0
enq: MW – contention	name|mode	Schedule Id	0
enq: OC – contention	name|mode	1	2
enq: OL – contention	name|mode	hash value	0
enq: OQ – xsoq*histrecb	name|mode	resource id	0
enq: OQ – xsoqhiAlloc	name|mode	resource id	0
enq: OQ – xsoqhiClose	name|mode	resource id	0
enq: OQ – xsoqhiFlush	name|mode	resource id	0
enq: OQ – xsoqhistrecb	name|mode	resource id	0
enq: OW – initialization	name|mode	0	0
enq: OW – termination	name|mode	0	0
enq: PD – contention	name|mode	property name	key hash
enq: PE – contention	name|mode	parno	0
enq: PF – contention	name|mode	0	0
enq: PG – contention	name|mode	0	0
enq: PH – contention	name|mode	0	0
enq: PI – contention	name|mode	operation	serial #
enq: PL – contention	name|mode	0	0
enq: PR – contention	name|mode	0	0
enq: PS – contention	name|mode	instance	slave ID
enq: PT – contention	name|mode	disk group #	type
enq: PV – syncshut	name|mode	0	0
enq: PV – syncstart	name|mode	0	0
enq: PW – flush prewarm buffers	name|mode	0	0
enq: PW – perwarm status in dbw0	name|mode	0	0
enq: RB – contention	name|mode	disk group	0
enq: RF – RF – Database Automatic Disable	name|mode	lock operation	lock value
enq: RF – RF – FSFO Observed	name|mode	lock operation	lock value
enq: RF – RF – FSFO connectivity	name|mode	lock operation	lock value
enq: RF – RF – FSFO state	name|mode	lock operation	lock value
enq: RF – RF – FSFO synchronization	name|mode	lock operation	lock value
enq: RF – RF – FSFO wait	name|mode	lock operation	lock value
enq: RF – atomicity	name|mode	lock operation	lock value
enq: RF – new AI	name|mode	lock operation	lock value
enq: RF – synch: DG Broker metadata	name|mode	lock operation	lock value
enq: RF – synchronization: HC master	name|mode	lock operation	lock value
enq: RF – synchronization: aifo master	name|mode	lock operation	lock value
enq: RF – synchronization: chief	name|mode	lock operation	lock value
enq: RF – synchronization: critical ai	name|mode	lock operation	lock value
enq: RN – contention	name|mode	thread number	log number
enq: RO – contention	name|mode	2	0
enq: RO – fast object reuse	name|mode	2	0
enq: RP – contention	name|mode	file #	1 or block
enq: RR – contention	name|mode	lock#	not used
enq: RS – file delete	name|mode	record type	record id
enq: RS – persist alert level	name|mode	record type	record id
enq: RS – prevent aging list update	name|mode	record type	record id
enq: RS – prevent file delete	name|mode	record type	record id
enq: RS – read alert level	name|mode	record type	record id
enq: RS – record reuse	name|mode	record type	record id
enq: RS – write alert level	name|mode	record type	record id
enq: RT – contention	name|mode	redo thread	type
enq: RU – contention	name|mode	0	0
enq: RU – waiting	name|mode	0	0
enq: RW – MV metadata contention	name|mode	table obj#	0
enq: SB – contention	name|mode	0	0
enq: SE – contention	name|mode	Session-id	Serial#
enq: SF – contention	name|mode	0	0
enq: SH – contention	name|mode	0	0
enq: SI – contention	name|mode	object #	0
enq: SK – contention	name|mode	tablespace #	dba
enq: SQ – contention	name|mode	object #	0
enq: SR – contention	name|mode	operation	sequence # / apply #
enq: SS – contention	name|mode	tablespace #	dba
enq: ST – contention	name|mode	0	0
enq: SU – contention	name|mode	table space #	0
enq: SW – contention	name|mode	0	0
enq: TA – contention	name|mode	operation	undo segment # / other
enq: TB – SQL Tuning Base Cache Load	name|mode	1	2
enq: TB – SQL Tuning Base Cache Update	name|mode	1	2
enq: TC – contention	name|mode	checkpoint ID	0
enq: TC – contention2	name|mode	checkpoint ID	0
enq: TD – KTF dump entries	name|mode	0	0
enq: TE – KTF broadcast	name|mode	0	0
enq: TF – contention	name|mode	tablespace #	relative file #
enq: TL – contention	name|mode	0	0
enq: TM – contention	name|mode	object #	table/partition
enq: TO – contention	name|mode	object #	1
enq: TQ – DDL contention	name|mode	QT_OBJ#	0
enq: TQ – INI contention	name|mode	QT_OBJ#	0
enq: TQ – TM contention	name|mode	QT_OBJ#	0
enq: TS – contention	name|mode	tablespace ID	dba
enq: TT – contention	name|mode	tablespace ID	operation
enq: TW – contention	name|mode	0	operation
enq: TX – allocate ITL entry	name|mode	usn<<16 | slot	sequence
enq: TX – contention	name|mode	usn<<16 | slot	sequence
enq: TX – index contention	name|mode	usn<<16 | slot	sequence
enq: TX – row lock contention	name|mode	usn<<16 | slot	sequence
enq: UL – contention	name|mode	id	0
enq: US – contention	name|mode	undo segment #	0
enq: WA – contention	name|mode	0	0
enq: WF – contention	name|mode	0	0
enq: WL – contention	name|mode	log # / thread id #	sequence #
enq: WP – contention	name|mode	0	0
enq: WR – contention	name|mode	thread id #	sequence #
enq: XH – contention	name|mode	0	0
enq: XQ – recovery	name|mode	disk group #	unused
enq: XQ – relocation	name|mode	disk group #	unused
enq: XR – database force logging	name|mode	operation	0
enq: XR – quiesce database	name|mode	operation	0
enq: XY – contention	name|mode	id1	id2
enq: ZG – contention	name|mode	file group id	version id

For the P1 values which is “name|mode”, we can decode it like this:

select chr(bitand(p1,-16777216)/16777215)||chr(bitand(p1, 16711680)/65535) "Name", bitand(p1, 65535) "Mode" from v$session;

Reference : Oracle Wait Interface: A Practical Guide to Performance Diagnostics & Tuning
                   https://alexzeng.wordpress.com/2013/07/16/enqueue-waits-in-oracle-database-10g/