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Databases & SQL vocabulary · Transactions and Concurrency

ACID

Meaning in databases & SQL, with examples

/ˈæsɪd/abbreviationCore term

In databases & SQL, ACID means: Atomicity, Consistency, Isolation, Durability: the four guarantees that make database transactions reliable even with errors, crashes and many users at once.

In Turkish: ACID özellikleri

How it is used

A favourite interview question. People say a database is 'ACID-compliant' or offers 'full ACID transactions'. Relational databases are ACID by design; many NoSQL systems trade some of these guarantees for scale, although several now offer ACID transactions too.

Example sentences

  1. We need ACID guarantees for the ledger, so it stays in PostgreSQL.

  2. Can you explain what each letter in ACID means?

Common collocations

  • ACID-compliant
  • ACID transactions
  • ACID guarantees
  • ACID properties
  • transactionA group of database operations that are treated as one unit: either all of them succeed together or none of them is applied.
  • isolation levelA setting that controls how much one transaction can see of other transactions' changes, trading data safety against speed and concurrency.
  • commitTo end a transaction and make all of its changes permanent, so that other sessions can see them and they survive a crash.
  • eventual consistencyA guarantee that, if no new changes are made, all copies of the data will become the same after a short time, although reads may briefly return old values.

This word in other fields

The same English word can have a different meaning in another field:

More terms: Transactions and Concurrency

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