Deadlocks causing transaction failures and timeouts

Concurrent transactions block each other waiting for locks, detected when blocked_locks and blocking_locks have matching resources but different PIDs and blocked_locks.GRANTED is false

Identify deadlocks by joining pg_locks and pg_stat_activity to find blocked and blocking PIDs. Prevent with statement_timeout to limit lock wait time. Use pg_try_advisory_lock for application-level lock coordination to avoid database-level deadlocks.