Glossary term
What is Deadlock? Meaning for developers
In System Design
Two tasks each wait for the other forever. Example: Two cars blocking each other on a narrow bridge.
Learn it properly · System DesignLesson 4: Processes, Threads & Concurrency for Backend EngineersMost backend work is waiting. How one server juggles thousands of requests — processes, threads, event loops and lightweight threads — and the race conditions, deadlocks and pool limits that appear the moment it does.In SQL & PostgreSQL
Two transactions each wait for a lock the other holds. PostgreSQL stops one with an error.
Learn it properly · SQL & PostgreSQLLesson 6: Transactions, Isolation Levels and LocksAtomicity, read committed versus repeatable read versus serializable with two real sessions, row locks, SKIP LOCKED, deadlocks and retries.