Q:

Unresponsive Table - Completely frozen

I came in this morning and one of my staging tables is completely unresponsive.  Any query involving the table runs indefintely or until timeout.  I can't even do SELECT OBJECT_ID('staging.mytable') as it will run forever.  I've tested this across several different computers so the problem isn't in the client (ssms).  I see no hanging processes in Profiler.  Any queries involving the table in question just start and then wait.  I cannot drop or truncate the table.
Any ideas on where to go from here?  Its just a staging table so there's no real loss in dropping it, but it is gumming up the works right now across all of my procs/scripts.

A:

There are a few different ways to troubleshoot this when it happens. 
1) Use sp_who2 (ms_shipped proc) or use sp_whoisactive (way better, written by MVP Adam Machanic, have to download it and run the script in SSMS to create the proc) that will show running processes and who is running them. Find the ones that are blocking and go from there. 
2) launch the activity monitor with ctl+alt+A and filter the running sessions for blocked or head blocker to see who is running a process that is blocking others. 

