SQL Server Error 1205: "Deadlock victim" — Where to Find the Graph?
Extracting the deadlock graph from the system_health Extended Events ring buffer, understanding victim election, and architectural resolution.
The error string is a symptom, not the root cause. Do not restart the server blindly. Run the diagnostic queries below to pinpoint the actual failure mode.
▸Symptom
Transaction (Process ID 87) was deadlocked on lock resources and has been chosen as the deadlock victim.SQL Server automatically logs deadlock XML graphs in the default system_health Extended Events session.
▸Extract Deadlock Graph via SQL
SELECT CAST(t.target_data AS XML) AS deadlock_xml
FROM sys.dm_xe_session_targets t
JOIN sys.dm_xe_sessions s ON s.address = t.event_session_address
WHERE s.name = 'system_health' AND t.target_name = 'ring_buffer';▸Mitigations
- 1Enable Read Committed Snapshot Isolation (RCSI):
ALTER DATABASE db_name SET READ_COMMITTED_SNAPSHOT ON; - 2Enforce consistent object access ordering in application logic.
- 3Lower priority on analytical queries:
SET DEADLOCK_PRIORITY LOW;
- •Validated versions: SQL Server 2019 / 2022
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