How to find blocking in SQL Server ?

      Blocking:

·         The following query is used to determine the blocking sessions:

select blocking_session_id, wait_duration_ms, session_id from

sys.dm_os_waiting_tasks

where blocking_session_id is not null

·         The following query is used to identify the query is executed currently for blocking:

dbcc INPUTBUFFER(session_id)

·         The following query is used to find out the spid that is blocking another spid:

Sp_who