Transaction Deadlock Detection

Transaction Deadlock Detection is a SQL statement in the Transactions category. Deadlock detection and prevention strategies. The database chooses a deadlock victim and rolls back its transaction. The syntax is -- Deadlock: two transactions each hold locks the other needs. DB kills one (deadlock victim).. It returns deadlock handling. A typical example: -- SQL Server: view deadlocks SELECT xdr.value('(/deadlock/victim-list/victimProcess/@id)[1]', 'int') AS victim_id FROM (SELECT CAST(event_data AS XML) AS ed FROM sys.fn_xe_file_target_read_file( 'C:\Program Files\...\system_health*.xel', NULL, NULL, NULL)) AS f CROSS APPLY ed.nodes('/event/data/value/deadlock') AS xdr(xd); -- Prevention strategies: -- 1. Always access tables in the same order -- 2. Keep transactions short -- 3. Use lower isolation levels when appropriate -- 4. Implement retry logic in application code -- 5. Use indexes to reduce… A close relative is BEGIN / START TRANSACTION, which begins a new transaction. Changes made within are invisible to others until COMMIT. A close relative is COMMIT, which saves all changes made in the current transaction permanently.