[T-SQL] Identify Blocking Query / Session

One of the most common problem that DBA faces is that one or many sessions get blocked by some sessions due to long execution or deadlock. I have many times faced this problem and also read the same problem which is faced by many DBAs every day.

Here is the query by which you can kill the blocking session:
Kill 3 ( 3 is the blocking session )

But now your question would be how to identify the blocking session , so here we go...

SELECT


db.name DBName,

tl.request_session_id,

wt.blocking_session_id,

OBJECT_NAME(p.OBJECT_ID) BlockedObjectName,

tl.resource_type,

h1.TEXT AS RequestingText,

h2.TEXT AS BlockingTest,

tl.request_mode

FROM sys.dm_tran_locks AS tl

INNER JOIN sys.databases db ON db.database_id = tl.resource_database_id

INNER JOIN sys.dm_os_waiting_tasks AS wt ON tl.lock_owner_address = wt.resource_address

INNER JOIN sys.partitions AS p ON p.hobt_id = tl.resource_associated_entity_id

INNER JOIN sys.dm_exec_connections ec1 ON ec1.session_id = tl.request_session_id

INNER JOIN sys.dm_exec_connections ec2 ON ec2.session_id = wt.blocking_session_id

CROSS APPLY sys.dm_exec_sql_text(ec1.most_recent_sql_handle) AS h1

CROSS APPLY sys.dm_exec_sql_text(ec2.most_recent_sql_handle) AS h2

GO