Loading Academy Hub...
Diagnose lock wait queues, isolation level conflicts, and automated rollback triggers in enterprise transactional pipelines.
Deadlocks occur when Transaction 1 holds Resource A and requests Resource B, while Transaction 2 holds Resource B and requests Resource A.
SET lock_timeout = '5s'; to fail fast instead of hanging ETL workers.SELECT blocked_locks.pid AS blocked_pid,
blocking_locks.pid AS blocking_pid,
blocked_activity.query AS blocked_statement,
blocking_activity.query AS current_statement_in_blocking_process
FROM pg_catalog.pg_locks blocked_locks
JOIN pg_catalog.pg_stat_activity blocked_activity ON blocked_activity.pid = blocked_locks.pid
JOIN pg_catalog.pg_locks blocking_locks
ON blocking_locks.locktype = blocked_locks.locktype
AND blocking_locks.DATABASE IS NOT DISTINCT FROM blocked_locks.DATABASE
AND blocking_locks.relation IS NOT DISTINCT FROM blocked_locks.relation
AND blocking_locks.page IS NOT DISTINCT FROM blocked_locks.page
AND blocking_locks.tuple IS NOT DISTINCT FROM blocked_locks.tuple
AND blocking_locks.virtualxid IS NOT DISTINCT FROM blocked_locks.virtualxid
AND blocking_locks.transactionid IS NOT DISTINCT FROM blocked_locks.transactionid
AND blocking_locks.classid IS NOT DISTINCT FROM blocked_locks.classid
AND blocking_locks.objid IS NOT DISTINCT FROM blocked_locks.objid
AND blocking_locks.objsubid IS NOT DISTINCT FROM blocked_locks.objsubid
AND blocking_locks.pid != blocked_locks.pid
JOIN pg_catalog.pg_stat_activity blocking_activity ON blocking_activity.pid = blocking_locks.pid
WHERE NOT blocked_locks.GRANTED;
Review the production code, company interview Q&As, incident traces, and comprehension quiz inside this lesson.
-- Production Resilient Transaction Template with Lock Timeout & Rollback BEGIN; -- Prevent query from hanging pipelines forever if locked SET LOCAL lock_timeout = '10s'; SET LOCAL statement_timeout = '60s'; -- Deterministic update order by primary key UPDATE accounts SET balance = balance - 500 WHERE account_id = 101; UPDATE accounts SET balance = balance + 500 WHERE account_id = 205; COMMIT;
ERROR: canceling statement due to statement timeout (timeout=30000ms)