Answer
Blocking is identified using:
- sys.dm_exec_requests – blocking_session_id
- sys.dm_os_waiting_tasks – wait chains
- Activity Monitor – high-level visualization
Blocking chains often originate from a long-running transaction holding critical locks.
Quick Answer
Use sys.dm_exec_requests to see currently waiting sessions and what they're waiting for. sys.dm_os_waiting_tasks shows the blocking chain — who is waiting on whom. The session at the head of the chain with no wait is the blocker. That's the transaction to investigate — long-running or uncommitted transactions are the usual culprit.
S
SugharaIQ Editorial Team
Verified Answer
This answer has been peer-reviewed by industry experts holding senior engineering roles to ensure technical accuracy and relevance for modern interview standards.
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Source: SugharaIQ