In addition to sp_who, sp_lock can help identify processes that are blocking other processes. If the blk_spid column in the sp_who report indicates that another process has been blocked while waiting to acquire locks, sp_lock can display information about the blocking process. For example, process 10 in the sp_who output above is blocked by process 7. To see information about process 7, execute:
sp_lock 7
For more information about locking in Adaptive Server, see the Performance and Tuning Series: Locking and Concurrency Control.
