ACID
/AS-id/ · noun · Development · Origin: 1983
Definitions
An acronym for the four properties that guarantee reliable database transactions: Atomicity (all or nothing), Consistency (data stays valid), Isolation (concurrent transactions don't interfere), and Durability (committed data survives crashes). ACID compliance is what separates databases you'd trust with money from those you wouldn't.
In plain English: Four promises a database makes about reliability: everything happens completely or not at all, data stays valid, simultaneous operations don't clash, and saved data survives crashes.
Example: We can't use that NoSQL store for financial records — it doesn't provide ACID guarantees, so a crash mid-transfer could lose money.
Etymology
- 1970
- Edgar Codd publishes the relational model, implicitly requiring transaction integrity properties.
- 1983
- Theo Haerder and Andreas Reuter coin the ACID acronym (Atomicity, Consistency, Isolation, Durability) in a seminal paper.
- 1990s
- Enterprise databases (Oracle, SQL Server, PostgreSQL) compete on ACID compliance as a key selling point.
- 2010s
- The NoSQL movement challenges strict ACID in favor of eventual consistency (BASE), sparking debate about trade-offs.
Origin Story
The four guarantees that keep your database from lying to you
**ACID** (Atomicity, Consistency, Isolation, Durability) was coined by Andreas Reuter and Theo Harder in their 1983 paper 'Principles of Transaction-Oriented Database Recovery.' The acronym codified properties that database researchers had been discussing since the 1970s.
**Atomicity**: transactions are all-or-nothing. **Consistency**: transactions move the database from one valid state to another. **Isolation**: concurrent transactions don't interfere. **Durability**: committed data survives crashes. Together, they make databases trustworthy.
The NoSQL movement of the 2010s deliberately relaxed ACID guarantees for performance and scalability, coining **BASE** (Basically Available, Soft state, Eventually consistent) as a cheeky counterpart. The pendulum has since swung back -- distributed databases like CockroachDB and Spanner now offer ACID at scale.
Coined by: Andreas Reuter, Theo Harder
Context: 'Principles of Transaction-Oriented Database Recovery,' 1983
Fun fact: The ACID/BASE acronym war is one of computer science's best naming jokes. ACID and BASE are chemical opposites (acids vs bases), and the database properties they represent are philosophical opposites too. Someone in the NoSQL community clearly had a sense of humor.