How to check to table locking in SQL Server 2008 R2.

We used to use SP_LOCK and SP_LOCK2, but have since learned that the recommend method to determine locks is the code below as the two procs are to be deprecated in future releases.

Microsoft says the better way is to use the sys.dm_tran_locks dynamic management views.



The following code will select from the sys.dm_tran_locks and sys.partitions system tables.

More information on Locks can be found at the following Microsoft library pages:

Lock Modes

Locking Granularity

Key Range Locking





---------------------------------------------------------------
--  Code to find out what table is locked and the lock reason
---------------------------------------------------------------
select
    object_name(P.object_id) as TableName
    , resource_type
    , resource_description
    , request_mode
    , CASE REQUEST_MODE
                    WHEN 'S'        THEN 'Shared'
                    WHEN 'U'        THEN 'Update'
                    WHEN 'X'        THEN 'Exclusive'
                    WHEN 'IS'       THEN 'Intent Shared'
                    WHEN 'IU'       THEN 'Intent Update'
                    WHEN 'IX'       THEN 'Intent Exclusive'
                    WHEN 'SIU'      THEN 'Shared Intent Update'
                    WHEN 'SIX'      THEN 'Shared Intent Exclusive'
                    WHEN 'UIX'      THEN 'Update Intent Exclusive'
                    WHEN 'BU'       THEN 'Bulk Update'
                    WHEN 'RangeS_S' THEN 'Shared Range S'
                    WHEN 'RangeS_U' THEN 'Shared Range U'
                    WHEN 'RangeI_N' THEN 'Insert Range'
                    WHEN 'RangeI_S' THEN 'Insert Range S'
                    WHEN 'RangeI_U' THEN 'Insert Range U'
                    WHEN 'RangeI_X' THEN 'Insert Range X'
                    WHEN 'RangeX_S' THEN 'Exclusive range S'
                    WHEN 'RangeX_U' THEN 'Exclusive range U'
                    WHEN 'RangeX_X' THEN 'Exclusive range X'
                    WHEN 'SCH-M'    THEN 'Schema-Modification'
                    WHEN 'SCH-S'    THEN 'Schema-Stability'

        ELSE NULL
        END AS REQUEST_LOCK_MODE

FROM   sys.dm_tran_locks   AS L
       join sys.partitions AS P
        on L.resource_associated_entity_id = p.hobt_id