To obtain information about locks in the SQL Server Database Engine, use the sys. dm_tran_locks dynamic management view.
Expand server – management-currentActivity-expand Locks/object you can see locks by object information. Expand-server-management-double click Activity Monitor. on left side you have three options to choose from, select those options and you can see all the locks related information.
In MySQL, locked tables are identified using the SHOW OPEN TABLES command. In its simplest form is displays all locked tables. All open tables in the table cache are listed, but the IN_USE column indicates of the table is locked. When the first lock is taken, the value increments to 1.
SHOW OPEN TABLES WHERE `Table` LIKE '%[TABLE_NAME]%' AND `Database` LIKE '[DBNAME]' AND In_use > 0; to check any locked tables in a database. Show activity on this post. You can use SHOW OPEN TABLES to show each table's lock status.
This is not exactly showing you which rows are locked, but this may helpful to you.
You can check which statements are blocked by running this:
select cmd,* from sys.sysprocesses
where blocked > 0
It will also tell you what each block is waiting on. So you can trace that all the way up to see which statement caused the first block that caused the other blocks.
Edit to add comment from @MikeBlandford:
The blocked column indicates the spid of the blocking process. You can run kill {spid} to fix it.
To add to the other responses, sp_lock
can also be used to dump full lock information on all running processes. The output can be overwhelming, but if you want to know exactly what is locked, it's a valuable one to run. I usually use it along with sp_who2
to quickly zero in on locking problems.
There are multiple different versions of "friendlier" sp_lock
procedures available online, depending on the version of SQL Server in question.
In your case, for SQL Server 2005, sp_lock
is still available, but deprecated, so it's now recommended to use the sys.dm_tran_locks
view for this kind of thing. You can find an example of how to "roll your own" sp_lock function here.
You can find current locks on your table by following query.
USE yourdatabase;
GO
SELECT * FROM sys.dm_tran_locks
WHERE resource_database_id = DB_ID()
AND resource_associated_entity_id = OBJECT_ID(N'dbo.yourtablename');
See sys.dm_tran_locks
If multiple instances of the same request_owner_type exist, the request_owner_id column is used to distinguish each instance. For distributed transactions, the request_owner_type and the request_owner_guid columns will show the different entity information.
For example, Session S1 owns a shared lock on Table1; and transaction T1, which is running under session S1, also owns a shared lock on Table1. In this case, the resource_description column that is returned by sys.dm_tran_locks will show two instances of the same resource. The request_owner_type column will show one instance as a session and the other as a transaction. Also, the resource_owner_id column will have different values.
I use a Dynamic Management View (DMV) to capture locks as well as the object_id or partition_id of the item that is locked.
(MUST switch to the Database you want to observe to get object_id)
SELECT
TL.resource_type,
TL.resource_database_id,
TL.resource_associated_entity_id,
TL.request_mode,
TL.request_session_id,
WT.blocking_session_id,
O.name AS [object name],
O.type_desc AS [object descr],
P.partition_id AS [partition id],
P.rows AS [partition/page rows],
AU.type_desc AS [index descr],
AU.container_id AS [index/page container_id]
FROM sys.dm_tran_locks AS TL
INNER JOIN sys.dm_os_waiting_tasks AS WT
ON TL.lock_owner_address = WT.resource_address
LEFT OUTER JOIN sys.objects AS O
ON O.object_id = TL.resource_associated_entity_id
LEFT OUTER JOIN sys.partitions AS P
ON P.hobt_id = TL.resource_associated_entity_id
LEFT OUTER JOIN sys.allocation_units AS AU
ON AU.allocation_unit_id = TL.resource_associated_entity_id;
You can also use the built-in sp_who2
stored procedure to get current blocked and blocking processes on a SQL Server instance. Typically you'd run this alongside a SQL Profiler instance to find a blocking process and look at the most recent command that spid issued in profiler.
You can find details via the below script.
-- List all Locks of the Current Database
SELECT TL.resource_type AS ResType
,TL.resource_description AS ResDescr
,TL.request_mode AS ReqMode
,TL.request_type AS ReqType
,TL.request_status AS ReqStatus
,TL.request_owner_type AS ReqOwnerType
,TAT.[name] AS TransName
,TAT.transaction_begin_time AS TransBegin
,DATEDIFF(ss, TAT.transaction_begin_time, GETDATE()) AS TransDura
,ES.session_id AS S_Id
,ES.login_name AS LoginName
,COALESCE(OBJ.name, PAROBJ.name) AS ObjectName
,PARIDX.name AS IndexName
,ES.host_name AS HostName
,ES.program_name AS ProgramName
FROM sys.dm_tran_locks AS TL
INNER JOIN sys.dm_exec_sessions AS ES
ON TL.request_session_id = ES.session_id
LEFT JOIN sys.dm_tran_active_transactions AS TAT
ON TL.request_owner_id = TAT.transaction_id
AND TL.request_owner_type = 'TRANSACTION'
LEFT JOIN sys.objects AS OBJ
ON TL.resource_associated_entity_id = OBJ.object_id
AND TL.resource_type = 'OBJECT'
LEFT JOIN sys.partitions AS PAR
ON TL.resource_associated_entity_id = PAR.hobt_id
AND TL.resource_type IN ('PAGE', 'KEY', 'RID', 'HOBT')
LEFT JOIN sys.objects AS PAROBJ
ON PAR.object_id = PAROBJ.object_id
LEFT JOIN sys.indexes AS PARIDX
ON PAR.object_id = PARIDX.object_id
AND PAR.index_id = PARIDX.index_id
WHERE TL.resource_database_id = DB_ID()
AND ES.session_id <> @@Spid -- Exclude "my" session
-- optional filter
AND TL.request_mode <> 'S' -- Exclude simple shared locks
ORDER BY TL.resource_type
,TL.request_mode
,TL.request_type
,TL.request_status
,ObjectName
,ES.login_name;
--TSQL commands
SELECT
db_name(rsc_dbid) AS 'DATABASE_NAME',
case rsc_type when 1 then 'null'
when 2 then 'DATABASE'
WHEN 3 THEN 'FILE'
WHEN 4 THEN 'INDEX'
WHEN 5 THEN 'TABLE'
WHEN 6 THEN 'PAGE'
WHEN 7 THEN 'KEY'
WHEN 8 THEN 'EXTEND'
WHEN 9 THEN 'RID ( ROW ID)'
WHEN 10 THEN 'APPLICATION' end AS 'REQUEST_TYPE',
CASE req_ownertype WHEN 1 THEN 'TRANSACTION'
WHEN 2 THEN 'CURSOR'
WHEN 3 THEN 'SESSION'
WHEN 4 THEN 'ExSESSION' END AS 'REQUEST_OWNERTYPE',
OBJECT_NAME(rsc_objid ,rsc_dbid) AS 'OBJECT_NAME',
PROCESS.HOSTNAME ,
PROCESS.program_name ,
PROCESS.nt_domain ,
PROCESS.nt_username ,
PROCESS.program_name ,
SQLTEXT.text
FROM sys.syslockinfo LOCK JOIN
sys.sysprocesses PROCESS
ON LOCK.req_spid = PROCESS.spid
CROSS APPLY sys.dm_exec_sql_text(PROCESS.SQL_HANDLE) SQLTEXT
where 1=1
and db_name(rsc_dbid) = db_name()
--Lock on a specific object
SELECT *
FROM sys.dm_tran_locks
WHERE resource_database_id = DB_ID()
AND resource_associated_entity_id = object_id('Specific Table');
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