Lock:Acquired Event Class

THIS TOPIC APPLIES TO: yesSQL ServeryesAzure SQL DatabasenoAzure SQL Data Warehouse noParallel Data Warehouse

The Lock:Acquiredevent class indicates that acquisition of a lock on a resource, such as a data page, has been achieved.

The Lock:Acquired and Lock:Released event classes can be used to monitor when objects are being locked, the type of locks taken, and for how long the locks were retained. Locks retained for long periods of time may cause contention issues and should be investigated. For example, an application can be acquiring locks on rows in a table, and then waiting for user input. Because the user input can take a long time to occur, the locks can block other users. In this instance, the application should be redesigned to make lock requests only when needed and not require user input when locks have been acquired.

Lock:Acquired Event Class Data Columns

Data column name Data type Description Column ID Filterable
ApplicationName nvarchar Name of the client application that created the connection to an instance of Microsoft SQL Server. This column is populated with the values passed by the application rather than the displayed name of the program. 10 Yes
BigintData1 bigint Partition ID if the lock resource is partitioned. 52 Yes
BinaryData image Lock resource identifier. 2 Yes
ClientProcessID int ID assigned by the host computer to the process where the client application is running. This data column is populated if the client provides the client process ID. 9 Yes
DatabaseID int ID of the database in which the lock was acquired. SQL Server Profiler displays the name of the database if the ServerName data column is captured in the trace and the server is available. Determine the value for a database by using the DB_ID function. 3 Yes
Duration bigint Amount of time (in microseconds) between the time the lock request was issued and the time the lock was acquired. 13 Yes
EndTime datetime Time at which the event ended. 15 Yes
EventClass int Type of event = 24. 27 No
EventSequence int Sequence of a given event within the request. 51 No
GroupID int ID of the workload group where the SQL Trace event fires. 66 Yes
HostName nvarchar Name of the computer on which the client is running. This data column is populated if the client provides the host name. To determine the host name, use the HOST_NAME function. 8 Yes
IntegerData2 int Identified for informational purposes only. Not supported. Future compatibility is not guaranteed. 55 Yes
IsSystem int Indicates whether the event occurred on a system process or a user process. 1 = system, 0 = user. 60 Yes
LoginName nvarchar Name of the login of the user (either SQL Server security login or the Windows login credentials in the form of DOMAIN\username). 11 Yes
LoginSid image Security identification number (SID) of the logged-in user. You can find this information in the sys.server_principals catalog view. Each SID is unique for each login in the server. 41 Yes
Mode int Resulting mode after the lock was acquired.

0=NULL - Compatible with all other lock modes (LCK_M_NL)

1=Schema Stability lock (LCK_M_SCH_S)

2=Schema Modification Lock (LCK_M_SCH_M)

3=Shared Lock (LCK_M_S)

4=Update Lock (LCK_M_U)

5=Exclusive Lock (LCK_M_X)

6=Intent Shared Lock (LCK_M_IS)

7=Intent Update Lock (LCK_M_IU)

8=Intent Exclusive Lock (LCK_M_IX)

9=Shared with intent to Update (LCK_M_SIU)

10=Shared with Intent Exclusive (LCK_M_SIX)

11=Update with Intent Exclusive (LCK_M_UIX)

12=Bulk Update Lock (LCK_M_BU)

13=Key range Shared/Shared (LCK_M_RS_S)

14=Key range Shared/Update (LCK_M_RS_U)

15=Key Range Insert NULL (LCK_M_RI_NL)

16=Key Range Insert Shared (LCK_M_RI_S)

17=Key Range Insert Update (LCK_M_RI_U)

18=Key Range Insert Exclusive (LCK_M_RI_X)

19=Key Range Exclusive Shared (LCK_M_RX_S)

20=Key Range Exclusive Update (LCK_M_RX_U)

21=Key Range Exclusive Exclusive (LCK_M_RX_X)
32 Yes
NTDomainName nvarchar Windows domain to which the user belongs. 7 Yes
NTUserName nvarchar Windows user name. 6 Yes
ObjectID int ID of the object on which the lock was acquired, if available and applicable. 22 Yes
ObjectID2 bigint ID of the related object or entity, if available and applicable. 56 Yes
OwnerID int 1=TRANSACTION

2=CURSOR

3=SESSION

4=SHARED_TRANSACTION_WORKSPACE

5=EXCLUSIVE_TRANSACTION_WORKSPACE
58 Yes
RequestID int ID of the request containing the statement. 49 Yes
ServerName nvarchar Name of the instance of SQL Server being traced. 26 No
SessionLoginName nvarchar Login name of the user who originated the session. For example, if you connect to SQL Server using Login1 and execute a statement as Login2, SessionLoginName shows Login1 and LoginName shows Login2. This column displays both SQL Server and Windows logins. 64 Yes
SPID int ID of the session on which the event occurred. 12 Yes
StartTime datetime Time at which the event started, if available. 14 Yes
TextData ntext Text value dependent on the lock type that was acquired. This is the same value as the resource_description column in sys.dm_tran_locks. 1 Yes
TransactionID bigint System-assigned ID of the transaction. 4 Yes
Type int 1=NULL_RESOURCE

2=DATABASE

3=FILE

5=OBJECT

6=PAGE

7=KEY

8=EXTENT

9=RID

10=APPLICATION

11=METADATA

12=AUTONAMEDB

13=HOBT

14=ALLOCATION_UNIT
57 Yes

See Also

Lock:Released Event Class
sp_trace_setevent (Transact-SQL)
sys.dm_tran_locks (Transact-SQL)