Blocking occurs when two or more rows are locked by one SQL connection and a second connection to the SQL server requires a conflicting on lock on those rows. This results in the second connection to wait until the first lock is released.

Troubleshooting blocking:

► SQL scripts can be written that constantly monitor the state of locking and blocking on SQL Server

► The common blocking scenarios must be identified and resolved.

► The scripts output must be checked constantly,

► The SQL profilers data must be examined regularly to detect blocking.