/*sp_who will return:
spid (system process id)
where spid 0 - 50 = MSSQL Reserved spid's
and spid >= 51 = User/application spid's
ecid (execution context id)
where 0 = parent thread
and 1,2,3...n = sub threads
status (process status)
loginname
blk = spid for blocking process
where 0 = no blocking process
and -2 = blocking orphan transaction
dbname = database used by process
cmd = SQL Server command executing for process
*/
USE master
EXEC sp_who