What does ACID actually stand for, and why do all four properties matter together?
Atomicity (all-or-nothing), Consistency (valid state to valid state), Isolation (concurrent transactions don't corrupt each other), Durability (once committed, it survives a crash). They matter together because dropping any one breaks the guarantee the others depend on — atomicity without isolation still lets concurrent transactions see each other's half-finished work.
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Database Transactions Explained: ACID, Isolation Levels, and Concurrency ControlWhat ACID actually guarantees, and how pessimistic vs optimistic concurrency control decide whether your app locks or retries under load.
Read the full analysisOther questions this article answers
- What's the practical difference between pessimistic and optimistic concurrency control?
- What is a race condition in a database transaction, and how does isolation prevent it?
- Why would a database ever allow a weaker isolation level than Serializable?
- What causes a deadlock, and how do databases resolve it?
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