http://blogs.msdn.com/microsoft_dynamics_nav_sustained_engineering/archive/2008/03/28/simple-query-to-check-the-recent-blocking-history.aspxSQL Server 2005 keeps (some) history of the number and time that blocking occurred on indexes. This blog contains a query that queries this information to help identifying on which tables blocking happens most. The query shows accumulated numbers (no.en-USCommunityServer 2.1 SP1 (Build: 61025.2)http://blogs.msdn.com/microsoft_dynamics_nav_sustained_engineering/archive/2008/03/28/simple-query-to-check-the-recent-blocking-history.aspx#9001335Thu, 16 Oct 2008 05:31:00 GMT91d46819-8472-40ad-a661-2c78acb4018c:9001335silva_nuno@hotmail.com<p>Hi,</p> <p>In the results of the query we get numeber of locks and number of blocks. Waht is the diference between the two columns?</p> <p>Thanks,</p> <p>Nuno</p> http://blogs.msdn.com/microsoft_dynamics_nav_sustained_engineering/archive/2008/03/28/simple-query-to-check-the-recent-blocking-history.aspx#9006918Mon, 20 Oct 2008 10:04:36 GMT91d46819-8472-40ad-a661-2c78acb4018c:9006918Lohndorf<p>Hello Nuno,</p> <p>A block is also a lock. But it becomes a block when another user tries to lock the same records.</p> <p>So, for example, you may have millions of lock on a table without causing any problems, if a process or user is the only one using that table. But, if you have users and processes locking the same records, then that is when you get blocks.</p> <p>I hope this explains?</p> <p>Lars</p>