ORACLE19C的鎖

文章目錄

• 鎖的類型和模式

鎖的類型和模式

oracle鎖的類型、名稱、描述可以通過v$lock_type來檢視

select * from v$lock_type
           

在oracle19c中，有291種鎖，其中大部分是資料庫内部的鎖，我們能經常見到的鎖類型很少。

v$lock_type的字段說明

編号	字段名稱	字段說明
1	TYPE	鎖的辨別，兩個字母的簡寫
2	NAME	鎖的名稱
3	ID1_TAG	排隊類型的描述
4	ID2_TAG	排隊類型的詳細資訊
5	IS_USER	使用者隊列，也就是這些隊列是由SQL發起并獲得的，應用程式很可能在這些隊列上出現死鎖，也就是這種死鎖被認為是程式錯誤
6	IS_RECYCLE	是否可重用，訓示隊列是否需要緩存DLM中關聯的資源，DLM是ORACLE得分布式鎖管理器，作用是協調執行個體間對資源的競争通路，也就是隻在RAC下該值才有意義，該字段有兩個值：
YES	表示不需要緩存
NO	表示需要緩存
7	DESCRIPTION	字段描述
8	CON_ID	資料所屬容器的ID

鎖類型的描述（19C）,從資料庫裡直接插出來的，後續再補充中文描述

TYPE	NAME	ID1_TAG	ID2_TAG	IS_USER	IS_RECYCLE	DESCRIPTION
AB	Auto BMR	operation	operation parm	NO	NO	A general class of locks used by auto BMR for various purposes
AC	Application Continuity	NO	NO	Synchronizes new service activation
AD	ASM Disk AU Lock	group and disk number	AU number	NO	NO	Synchronizes accesses to a specific ASM disk AU
AE	Edition Lock	edition obj#	pdbuid	NO	NO	Prevent Dropping an edition in use
AF	Advisor Framework	task id	NO	NO	This enqueue is used to serialize access to an advisor task
AG	Analytic Workspace Generation	workspace #	generation	NO	NO	Synchronizes generation use of a particular workspace
AH	ASM Relocation Lock High	group/file number	virtual extent number	NO	NO	Protects locked extent pointers during ASM file relocation
AK	GES Deadlock Test	id1	id2	NO	NO	Lock used for internal testing
AM	ASM Enqueue	id1	id2	NO	NO	ASM instance general-purpose enqueue
AO	MultiWriter Object Access	workspace #	object #	NO	NO	Synchronizes access to objects and scalar variables
AP	SPM Autopurge	NO	NO	This enqueue is used to serialize the purging of SQL plan baselines
AQ	Queue Partitioning local enqueue	QT_OBJ#	NO	NO	Synchronizes partition operations on queue table within instance
AR	ASM Relocation Lock	group/file number	virtual extent number	NO	NO	Protects locked extent pointers during ASM file relocation
AS	Service Operations	NO	NO	Synchronizes new service activation
AT	Alter Tablespace	NO	NO	Serializes ‘alter tablespace’ operations
AU	DBKR	NO	NO	This enqueue is used to serialize ADR purge operation
AV	ASM volume locks	persistent DG number	non-DG number enqs	NO	NO	id1 is for persistent DG number locking. id2 is for other volume serialization
AW	Analytic Workspace	operation	workspace #	NO	NO	Synchronizes access to Analytic Workspace resources
AY	KSXA Test Affinity Dictionary	Op1	Op2	NO	NO	Affinity Dictionary test affinity synchronization
AZ	Emon-SRVNTFN_Q Create	NO	NO	Synchronize creation of AQ_SRVNTFN_Q among emon slaves
BA	non durable sub bmap alloc	NO	NO	Synchronizes access to globl Bitmap Alloc
BB	Global Transaction Branch	gtrid hash value	bqual hash value	NO	YES	2PC distributed transaction branch across RAC instances
BC	BA Container	container group	container id	NO	NO	Backup Appliance Container
BE	Critical Block Allocation	tablespace#	block#	NO	NO	Lock used to serialize allocation of critical blocks
BF	BLOOM FILTER	node#/parallelizer#	bloom#	NO	NO	Synchronize access to a bloom filter in a parallel statement
BI	BA Contained File Identification	group ID / file ID	file ID	NO	NO	Backup Appliance Contained File Identification
BM	clonedb bitmap file access	block number	number of blocks	NO	NO	synchronizes clonedb bitmap file operations
BO	DRM Banned-Object List	NO	NO	Coordinates dynamic remastering banned-object list
BR	Backup/Restore	operation	file #	NO	NO	Lock held by a backup/restore operation to allow other operations to wait for it
BS	Backup/Restore spare enq	id1	id2	NO	NO	KRB space usage
BU	Buddy Instance Context	NO	NO	synchronizes access to Recovery Set constructed by RMS0
BV	BA Group Rebuild/Validate	amrv$ key	NO	NO	Backup Appliance Container Rebuild/Validate
BZ	BA Contained File Resize	group ID / file ID	file ID	NO	NO	Backup Appliance Contained File Resize
CA	Calibration	NO	NO	Lock used by IO Calibration
CB	CBAC Master Lock	NO	NO	Synchronizes accesses to the CBAC roles cached in KGL
CC	Column Key	NO	NO	Serializes Column Encryption Key Cache
CF	Controlfile Transaction	operation	NO	NO	Synchronizes accesses to the controlfile
CI	Cross-Instance Call Invocation	opcode	type	NO	NO	Coordinates cross-instance function invocations
CL	Label Security cache	object #	NO	NO	Synchronizes accesses to label cache and label tables
CM	ASM Instance Enqueue	disk group #	type	NO	NO	ASM instance and gate enqueue
CN	KTCN REG enq	reg id	NO	NO	Enqueue held for registrations for change notifications
CO	KTUCLO Master Slave enq	inst id	NO	NO	Enqueue held for determining Master Slaves
CP	Pluggable Database	Internal	Internal	NO	NO	Coordinate pluggable database operations
CQ	Cleanup querycache registrations	NO	NO	Serializes access to cleanup client query cache registrations
CR	Reuse Block Range	2	NO	NO	Coordinates checkpointing of block range reuse
CT	Block Change Tracking	operation	operation parm	NO	YES	A general class of locks used by change tracking for various purposes
CU	Cursor	handle	handle	NO	NO	Recovers cursors in case of death while compiling
CX	TEXT: Index Specific Lock	Index Id	Partition Id	NO	NO	Index Specific Lock on CTX index
DA	Instance DP Array	NO	NO	Slave Process Spawn reservation and synchronization
DB	DbsDriver	EnqMode	NO	NO	Synchronizes modification of database wide supplementallogging attributes
DD	ASM Local Disk Group	disk group	type	NO	NO	Synchronizes local accesses to ASM disk groups
DE	Planned Draining RAC enqueue	NO	NO	Enqueue to serialize draining structure updates
DF	Datafile Online in RAC	file #	NO	NO	Enqueue held by foreground or DBWR when a datafile is brought online in RAC
DG	ASM Disk Group Modification	disk group	type	NO	NO	Synchronizes accesses to ASM disk groups
DI	GES Internal	NO	NO	Coordinates Global Enqueue Service deadlock detection
DL	Direct Loader Index Creation	object #	NO	NO	Lock to prevent index DDL during direct load
DM	Database Mount/Open	type	type	NO	NO	Enqueue held by foreground or DBWR to synchronize database mount/open or pluggable database open with other operations
DN	Diskgroup number generator	NO	NO	Serializes Group number generations
DO	ASM Disk Online Lock	disk group #	disk #	NO	NO	Synchronizes disk onlines and their recovery
DP	LDAP Parameter	NO	NO	Synchronizes access to LDAP parameters
DQ	ASM RBAL doorbell	disk group	NO	NO	Inter-RBAL process metadata invalidation notification
DR	Distributed Recovery	NO	NO	Serializes the active distributed recovery operation
DS	Database Suspend	NO	NO	Prevents a database suspend during LMON reconfiguration
DT	Default Temporary Tablespace	NO	NO	Serializes changing the default temporary table space and user creation
DV	Diana Versioning	object #	NO	NO	Synchronizes access to lower-version Diana (PL/SQL intermediate representation)
DW	In memory Dispenser	tablespace #	dba	NO	NO	Serialize in memory dispenser operations
DX	Distributed Transaction	transaction entry #	NO	YES	Serializes tightly coupled distributed transaction branches
E	Library Cache Lock 2	hash value	hash value	NO	NO	Synchronizes accesses to library cache objects
FA	ASM File Access Lock	disk group number	file number	NO	NO	Synchronizes accesses to open ASM files
FB	Format Block	tablespace #	dba	NO	NO	Ensures that only one process can format data blocks in auto segment space managed tablespaces
FC	Disk Group Chunk Mount	disk group	thread	NO	NO	controls access to an ACD chunk
FD	Flashback Database	Internal	Internal	NO	NO	Coordinate flashback database
FE	KTFA Recovery	NO	NO	Flashback archive Enqueue to serialize recovery
FG	ACD Relocation Gate Enqueue	disk group	type	NO	NO	ACD relocation serialization
FH	Flush Stat	Instance ID	NO	NO	Serializes flush of ILM stats to disk
FL	Flashback database log	Log #	zero	NO	NO	Synchronize access to flashback database log
FM	File Mapping	NO	NO	Synchronizes access to global file mapping state
FO	Oracle File System Operation	NO	NO	Synchronize Oracle File System Operations
FP	File Object	low file obj add	high file obj add	NO	NO	Synchronizes various File Object(FOB) operations
FR	Disk Group Recovery	disk group	thread	NO	NO	enqueue to control ASM recovery
FS	File Set / Dictionary Check	0 or pdbid	type	NO	NO	Enqueue used to synchronize recovery and file operations or synchronize dictionary check
FT	Disk Group Redo Generation	disk group	thread	NO	NO	controls the privilege to generate redo in a thread
FU	DBFUS	NO	NO	This enqueue is used to serialize the capture of the DB Feature Usage and High Water Mark Statistics
FW	Flashback Writer	NO	NO	Coordinate RVWR on multiple instances
FX	ACD Xtnt Info CIC	disk group	unused	NO	NO	serialize ACD relocation CIC
FZ	ASM Freezing Cache Lock	group number	NO	NO	Freezes ASM Cache for a diskgroup
G	Library Cache Pin 2	hash value	hash value	NO	NO	Synchronizes accesses to the contents of library cache objects
HC	HSM cache	NO	NO	Add or Remove from HSM cache
HD	ASM Disk Header	disk group	NO	NO	Serializes accesses to ASM SGA data structures
HM	Hang Manager Test Resource	userid or 0	fileid or 4294967295	NO	NO	Resource to Generate Hangs for Hang Manager Testing
HP	Queue Page	tablespace #	dba	NO	NO	Synchronizes accesses to queue pages
HQ	Hash Queue	object #	hash value	NO	NO	Synchronizes the creation of new queue IDs
HV	Direct Loader High Water Mark	object #	NO	NO	Lock used to broker the high water mark during parallel inserts
HW	Segment High Water Mark	table space #	block	NO	NO	Lock used to broker the high water mark during parallel inserts
IA	Internal	NO	NO
IC	IOServer Client	client id	none	NO	NO	Gets a unique client ID
ID	NID	NO	NO	Lock held by a NID operation to allow other operations to wait for it
IF	IOServer File	client id/group num	File number	NO	NO	Synchronizes file operations
II	IOS Instance fencing lock	instance number/incarn	client number/incarn	NO	NO	Signals fencing of a client in an instance
IK	IOS instance node fencing	cluster number	node number	NO	NO	Signals cluster/node fencing status
IL	Label Security	object #	NO	NO	Synchronizes accesses to internal label data structures
IM	Kti blr lock	pool #	NO	NO	Serializes block recovery for an IMU txn
IN	in-memory segment	tablespace #	dba	NO	NO	Serialize in-memory segment create/drop
IP	PDB Instance State	type	pdbuid	NO	NO	Enqueue used to synchronize instance state changes for PDBs
IR	Instance Recovery	0/1	NO	NO	Synchronizes instance recovery
IS	Instance State	0 or pdbid	type	NO	NO	Enqueue used to synchronize instance state changes
IT	In-Mem Temp Table Meta Creation	object #	NO	NO	Synchronizes accesses to a temp object’s metadata
IV	Library Cache Invalidation	object #	time stamp	NO	NO	Synchronizes library cache object invalidations across instances
IZ	INSTANCE LOCK	Lck name spc	NO	NO	Proctects the lock name space used by the instance
JD	Job Queue Date	NO	NO	Synchronizes dates between job queue coordinator and slave processes
JG	Job Scheduler1	service ID	queue type	NO	NO	Synchronizes accesses to the job cache1
JI	Materialized View	view object #	NO	NO	Lock held during materialized view operations (like refresh, alter) to prevent concurrent operations on the same materialized view
JQ	Job Queue	NO	NO	Lock to prevent multiple instances from running a single job
JS	Job Scheduler	service ID	queue type	NO	NO	Synchronizes accesses to the job cache
JX	SQL STATEMENT QUEUE	sqlid	execid	NO	NO	synchronize SQL statement queue operations
JZ	Join group dictionary	NO	NO	Synchronizes modifications to im_domain$ and im_joingroup$
KA	Kernel Service ACL	NO	NO	Global ACL State (Disabled=0/Enabled=1
KD	Scheduler Master DBRM	NO	NO	Determine DBRM master
KE	ASM Cached Attributes	group	entry	NO	NO	Synchronization of ASM cached attributes
KI	KJCI Serialization Enqueue	client opcode	NO	NO	Enqueue to Serialize KJCI Cross-Instance Calls
KK	Kick Instance to Switch Logs	redo thread	NO	NO	Lock held by open redo thread, used by other instances to force a log switch
KL	LOB KSI LOCK	kdlw lobid first half	kdlw lobid sec half	NO	NO	KSI lock for buffer cache and wgc concurrency
KM	Scheduler	type	type	NO	NO	Synchronizes various Resource Manager operations
KO	Multiple Object Checkpoint	2	NO	NO	Coordinates checkpointing of multiple objects
KP	Kupp Process Startup	NO	NO	Synchronizes kupp process startup
KQ	ASM Attributes Enque	group	entry	NO	NO	Single Inst Sync of ASM attributes
KR	Enqueue-Delete Rule	R_OBJ#	NO	NO	Synchronize delete rule and add rule to ruleset
KT	Scheduler Plan	plan #	NO	NO	Synchronizes accesses to the current Resource Manager plan
KV	KEY VECTOR	node#+sess#,cursor#+kv#	kv #	NO	NO	Synchronizes access to a key vector in an IMA query
KZ	ASM:Purge Audit	zero	zero	NO	NO	Coordinate GEN0 on multiple instances
L	Library Cache Lock 1	hash value	hash value	NO	NO	Synchronizes accesses to library cache objects
MC	SGA Log Operation	hash(logname)	NO	NO	Lock held during dml/ddl for a securefile log
MD	Materialized View Log DDL	master object #	NO	NO	Lock held during materialized view log DDL statements
MF	SGA Log-Bkt Flush	logid	bktId<<16	instid	NO	NO
MG	MGA service	qcserial#	rowsource#/mgacode#	NO	NO	synchronize MGA service
MH	AQ Notification Mail Host	NO	NO	Lock used for recovery when setting Mail Host for AQ e-mail notifications
MK	Master Key	NO	NO	Serializes enc$ access
ML	AQ Notification Mail Port	NO	NO	Lock used for recovery when setting Mail Port for AQ e-mail notifications
MM	MMON Management	NO	NO	MMON AutoTask Management
MN	LogMiner	session ID	NO	NO	Synchronizes updates to the LogMiner dictionary and prevents multiple instances from preparing the same LogMiner session
MO	MMON restricted session	NO	NO	Serialize MMON operations for restricted sessions
MP	SGA Log Partition	instid	logid	NO	NO	Lock held during partitioning an instance log
MR	Media Recovery	0 or file #	type	NO	NO	Lock used to coordinate media recovery with other uses of datafiles
MS	Materialized View Refresh Log	master object #	purpose	NO	NO	Lock held during materialized view refresh to setup MV log
MV	Online Datafile Move	type	file #	NO	NO	Synchronizes online datafile move operation or cleanup
MW	MWIN Schedule	Schedule Id	NO	NO	This enqueue is used to serialize the calibration of the manageability schedules with the Maintenance Window
MX	ksz synch	nodeid	instanceid	NO	NO	Used to synchronize storage server info across all nodes
N	Library Cache Pin 1	hash value	hash value	NO	NO	Synchronizes accesses to the contents of library cache objects
OC	Outline Cache	1	2	NO	NO	Synchronizes write accesses to the outline cache
OD	Online DDLs	object #	NO	NO	Lock to prevent concurrent online DDLs
OE	DLM Enqueue Owner Serialization	ownerID & 0xFFFFFFFF	ownerID >> 32	NO	NO	Enqueue to serialize access to an Omni Enqueue Owner
OL	Outline Name	hash value	NO	NO	Synchronizes accesses to a particular outline name
OP	Label Security Profile	object #	NO	NO	Synchronizes access to the ols$profile table
OQ	OLAPI Histories	resource id	NO	NO	Synchronizes access to olapi history resources
OT	TEXT: Generic Lock	NO	NO	Generic Lock on CTX index
OW	Encryption Wallet	NO	NO	Serializes wallet initialization and access
PA	Privilege Capture API	NO	NO	Lock held for modifying or reading a privilege capture
PB	PDB DDL Operations	type	NO	NO	Enqueue used to synchronize PDB DDL operations
PC	Enqueue for kzppctxs	NO	NO	Lock used for accesing kzppctx in SGA
PD	Property Lock	property name	key hash	NO	NO	Serializes property update
PE	Parameter	parno	NO	NO	Synchronizes system parameter updates
PF	Password File	NO	NO	Synchronizes accesses to the password file
PG	Global Parameter	NO	NO	Synchronizes global system parameter updates
PH	AQ Notification Proxy	NO	NO	Lock used for recovery when setting Proxy for AQ HTTP notifications
PI	Remote PX Process Spawn Status	operation	serial #	NO	NO	Communicates remote Parallel Execution Server Process creation status
PJ	DV Policy Admin API	NO	NO	Lock held for Database Vault policy administration API
PL	Transportable Tablespace	NO	NO	Coordinates plug-in operation of transportable tablespaces
PM	ASM PST Signalling	disk group #	type	NO	NO	Signals inter-instance access to ASM PST metadata
PP	GES Plug and Play Enqueue	NO	NO	Coordinates Adding Plug and Play Instances
PQ	Queue Ptning global enq	QT_OBJ#	NO	NO	Synchronizes partitioning operations on queue table accross instances
PR	Process Startup	type	dtp	NO	NO	Synchronizes process startup
PS	PX Process Reservation	instance	slave ID	NO	NO	Parallel Execution Server Process reservation and synchronization
PT	ASM Partnership and Status Table	disk group #	type	NO	NO	Gates inter-node synchronization of ASM PST metadata
PV	KSV slave startup	class id	NO	NO	Synchronizes slave start_shut
PW	Buffer Cache PreWarm	NO	NO	Coordinates Direct Loads with Prewarmed cache buffers
PX	PDB Recovery Operations	0 or thread#	type	NO	NO	Enqueue used to synchronize recovery-related PDB operations
PZ	Password File Metadata Cache	NO	NO	Synchronizes changes to the password file metadata cache
Q	Row Cache	hash value	hash value	NO	NO	Coordinates updates and accesses to row cache objects
RA	Real-Time ADDM Flood Control	NO	NO	Coordinate Flood Control in RAC
RB	ASM Rollback Recovery	disk group	NO	NO	Serializes ASM rollback recovery operations
RC	Result Cache: Enqueue	chunkNo	blockNo	NO	NO	Accessing a result in the result-set cache
RD	RAC Load	sqlid	execid	NO	NO	synchronize update of RAC load info
RE	Block Repair/Resilvering	File Type or File number	block number	NO	NO	Synchronizes block repair/mirror resilvering operations
RF	Data Guard Broker	lock operation	lock value	NO	NO	Synchronizes broker lock operation involving lock value
RG	Replication Global	NO	NO	Coordinates instance-wide replication / streams operations
RH	SQLQ Autopurge	NO	NO	This enqueue is used to serialize the purging of SQL quarantine configurations
RI	Reader Farm SQL Isolation	NO	NO	Reader Farm SQL Isolation
RK	wallet_set_mkey	NO	NO	Serializes wallet master key rekey
RL	RAC Encryption Wallet Lock	NO	NO	RAC encryption wallet lock
RM	GES Resource Remastering	NO	NO	Coordinates Global Enqueue Service resource remastering
RN	Redo Log Nab Computation	thread number	log number	NO	NO	Coordinates nab computations of online logs during recovery
RO	Multiple Object Reuse	2	NO	NO	Coordinates flushing of multiple objects
RP	Resilver / Repair	file #	1 or block	NO	NO	Enqueue held when resilvering is needed or when datablock is repaired from mirror
RQ	Enqueue-Cross SCN	Q_OBJ#	shard:mode	NO	NO	Synchronize enqueue-dequeue-cross on SCN generation
RR	Workload Capture and Replay	lock#	not used	NO	NO	Prevents concurrent invokers of DBMS_WORKLOAD_*
RS	Reclaimable Space	record type	record id	NO	NO	Lock held by a space reclaimable operation to allow other operations to wait for it
RT	Redo Thread	redo thread	type	NO	NO	Thread locks held by LGWR, DBW0, and RVWR to indicate mounted or open status
RU	Rolling Migration	NO	NO	Serilized rolling migration operations
RW	Materialized View Flags	table obj#	NO	NO	Lock used when creating or readingmaterialized view flags in detail tables
RX	ASM Extent Relocation Lock	disk group #:file #	virtual extent number	NO	NO	Synchronizes relocating ASM extents
RZ	RFS Logminer FLC	NO	NO	Synchronizes updates to logminer foreign log cache
SA	Purge SRL	NO	NO	Coordinates access to SRL by RFS and recovery process
SB	LogicalStandby	NO	NO	Synchronizes Logical Standby metadata operations
SC	System Change Number	NO	NO	Coordinates system change number generation on multiple instances
SE	Session Migration	Session-id	Serial#	NO	NO	Lock used by transparent session migration
SF	AQ Notification Sender	NO	NO	Lock used for recovery when setting Sender for AQ e-mail notifications
SG	OLS groups	object #	NO	NO	Synchronizes access to ols$groups table
SH	Active Session History Flushing	NO	NO	To prevent multiple concurrent flushers
SI	Streams Table Instantiation	object #	NO	NO	Prevents muiltiple streams table instantiations
SJ	KTSJ Slave Task Cancel	Slave process id	task id	NO	NO	Serializes cancelling task executed by slave process
SK	Shrink Segment	tablespace #	dba	NO	NO	Serialize shrink of a segment
SL	Serialize Lock request	kdlw lobid first half	kdlw lobid sec half	NO	NO	Request serialization to LCK0
SM	SMON Serialization	NO	NO	Lock to check SMON global work in RAC
SN	PDB SGA ALLOCATION	pdbid	NO	NO	Synchronize PDB SGA Allocation
SO	Shared Object	object #	NO	NO	Synchronizes access to Shared Object(PL/SQL Shared Object Manager)
SP	Spare Enqueue 0	id1	id2	NO	NO	Spare enqueue 0 for one-off backports
SQ	Sequence Cache	object #	NO	NO	Lock to ensure that only one process can replenish the sequence cache
SR	Synchronized Replication	operation	sequence # / apply #	NO	NO	Coordinates replication / streams operations
SS	Sort Segment	tablespace #	dba	NO	NO	Ensures that sort segments created during parallel DML operations aren’t prematurely cleaned up
ST	Space Transaction	NO	NO	Synchronizes space management activities in dictionary-managed tablespaces
SU	SaveUndo Segment	table space #	NO	NO	Serializes access to SaveUndo Segment
SV	Sequence Ordering	object #	NO	NO	Lock to ensure ordered sequence allocation in RAC mode
SW	Suspend Writes	NO	NO	Coordinates the ‘alter system suspend’ operation
SX	Spare Enqueue 1	id1	id2	NO	NO	Spare enqueue 1 for one-off backports
SY	IM chunk populate	tablespace # & objd	rdba	NO	NO	Lock used to serialize in-memory chunk populates
SZ	IM segment populate	tablespace #	rdba	NO	NO	Lock used to serialize in-memory segment populates
TA	Instance Undo	operation	undo segment # / other	NO	NO	Serializes operations on undo segments and undo tablespaces
TB	SQL Tuning Base Existence Cache	1	2	NO	NO	Synchronizes writes to the SQL Tuning Base Existence Cache
TC	Tablespace Checkpoint	checkpoint ID	NO	NO	Lock held to guarantee uniqueness of a tablespace checkpoint
TD	KTF map table enqueue	NO	NO	Serializes updates and inserts to the SMON_SCN_TIME mapping table
TE	KTF broadcast	NO	NO	Serializes broadcasts for flushes to SMON_SCN_TIME
TF	Temporary File	PDB ID & tablespace #	relative file #	NO	NO	Serializes dropping of a temporary file
TG	In Memory Temp Object	container id #	NO	NO	access to imcdt global resource
TH	Threshold Chain	NO	NO	Serializes threshold in-memory chain access
TI	In Memory Temp Object HT	query exec id #	qc session id #	NO	NO	access to an imcdt object HT
TK	Auto Task Serialization	0-MMON, 1-MMON Slave	NO	NO	Prevents more than one AutoTask Background Slave from being spawned
TL	Log Lock	NO	NO	Serializes threshold log table read and update
TM	DML	object #	table/partition	YES	NO	Synchronizes accesses to an object
TO	Temp Object	object #	1	NO	NO	Synchronizes DDL and DML operations on a temp object
TP	Runtime Fixed Table Purge	NO	NO	Lock used for fixed runtime table purge and definition
TQ	Queue table enqueue	QT_OBJ#	Other=>0 pdbOpen=>1	NO	NO	Synchronizes access to queue table
TR	Tablespace Rekey	pdbid	ts#	NO	NO	Coordinates tablespace rekey
TS	Temporary Segment	tablespace ID	dba	NO	NO	Serializes accesses to temp segments
TT	Tablespace	tablespace ID	operation	NO	NO	Serializes DDL operations on tablespaces
TU	TOP UPD	NO	NO	Enqueue to serialize updates to topology data
TW	Cross-Instance Transaction	operation	NO	NO	Lock held by one instance to wait for transactions on all instances to finish
TX	Transaction	usn<<16	slot	sequence	YES	NO
TZ	in-memory	tablespace #	dba	NO	NO	Serialize in-memory area create/drop
UF	AWR undostat stat flush for PDB	NO	NO	This enqueue is used to serialize undo stat flush per PDB
UL	User-defined	id	YES	NO	Lock used by user applications
US	Undo Segment	undo segment #	NO	NO	Lock held to perform DDL on the undo segment
UT	Transfer Unified Audit Records	TRANSFER AUDIT RECORDS	NO	NO	Lock held for transfer of unified audit records
V	Library Cache Lock 3	hash value	hash value	NO	NO	Synchronizes accesses to library cache objects
WA	AQ Notification Watermark	NO	NO	Lock used for recovery when setting Watermark for memory usage in AQ notifications
WD	AWR mail package retrieval	NO	NO	Serialize retrieving AWR mail package
WE	AWR auto-export	NO	NO	Serialize auto-export of AWR data
WF	AWR Flush	NO	NO	This enqueue is used to serialize the flushing of snapshots
WG	Write gather local enqueue	kdlw lobid first half	kdlw lobid sec half	NO	NO	Long term lock on wgc file state
WI	AWR import	NO	NO	Serialize the import of AWR dump files
WL	Being Written Redo Log	log # / thread id #	sequence #	NO	NO	Coordinates access to redo log files and archive logs
WM	WLM Plan Operations	NO	NO	Synchronizes new WLM Plan activation
WN	read_write_snapshot	pluggable database id	snapshot name	NO	NO	Synchronizes read write snapshot creation
WP	AWR Purge	NO	NO	This enqueue handles concurrency between purging and baselines
WR	LNS archiving log	thread id #	sequence #	NO	NO	Coordinates access to logs by Async LNS and ARCH/FG
WS	Logwriter member	mount ID	NO	NO	Used by Logwriter to coordinate communication to databases
WT	AWR CDB-Wide Table Lock	NO	NO	This enqueue serializes CDB-Wide Operation on AWR Table
XB	ASM Group Block lock	zero	zero	NO	NO	Prevents client diskgroup use during storage reconfiguration
XC	XDB Configuration	NO	NO	Synchronization access to XDB configuration
XD	Auto Online Exadata disks	opcode	notused	NO	NO	Serialize Auto Management of Exadata disks
XH	AQ Notification No-Proxy	NO	NO	Lock used for recovery when setting No Proxy Domains for AQ HTTP notifications
XK	GES Test-Lock for KSIRESTXDV	id1	id2	NO	NO	Lock used for internal testing
XL	ASM Extent Fault Lock	map id	nothing	NO	NO	Keep multiple processes from faulting in the same extent chunk
XM	RM Master Lock	zero	zero	NO	NO	RMON which process this lock is the Master
XQ	ASM Extent Relocation Enqueue	disk group #	unused	NO	NO	ASM extent relocation
XR	Quiesce / Force Logging	operation	NO	NO	Lock held during database quiesce or for database force logging
XY	Internal Test	id1	id2	NO	NO	Lock used for internal testing
Y	Library Cache Pin 3	hash value	hash value	NO	NO	Synchronizes accesses to the contents of library cache objects
ZA	Audit Partition	KZAM Aud Partition	NO	NO	Lock held for adding partition to Aud table
ZB	in-memory TS	tablespace #	dba	NO	NO	Serialize in-memory tablespace create/drop
ZC	IM FastStart Admin	tsn#	objd#	NO	NO	Lock used to serialize in-memory FS tasks
ZD	IM FastStart CU	segid	startdba	NO	NO	Lock used to serialize in-memory FS CU
ZF	FGA Partition	KZAM Fga Partition	NO	NO	Lock held for adding partition to Fga table
ZG	File Group	file group id	version id	NO	NO	Coordinates file group operations
ZH	Compression Analyzer	obj#	ulevel	YES	NO	Synchronizes analysis and insert into compression$, prevents multiple threads analyzing the same table during a load
ZL	Foreign Log Maintenance	session ID	NO	NO	Synchronizes updates to foreign log metadata by LogMiner reader and RFS processes
ZP	Private Temp Table synchronize	sess#	ser#	NO	NO	Synchronizes add/remove/read of PTT-GTT mapping
ZQ	quiesce enq	ts#	dba	NO	NO	Serialize SMU create and load quiesce
ZR	ZDLRA Server	operation	id	NO	NO	Lock held by a recovery server operation to allow other operations to wait for it
ZS	Spillover Audit files	Spillover audit file	NO	NO	Lock held for exclusive access on a Spillover audit file
ZX	repopulation file access	filename	block number	NO	NO	synchronizes file operations during repopulation
ZZ	Global Context Action	KSBXIC Action	NO	NO	Lock held for updating Global context hash tables