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Software Engineering vocabulary · Databases and Persistence

CAP theorem

Meaning in software engineering, with examples

nounAdvanced term

In software engineering, CAP theorem means: The idea that when a network failure splits a distributed database, it must choose between consistency (same data everywhere) and availability (always answering).

In Turkish: CAP teoremi

How it is used

CAP stands for Consistency, Availability and Partition tolerance. Proposed by Eric Brewer in 2000 and later proven, it is often simplified as 'pick two of three'. It appears in system design interviews and in comparisons of NoSQL databases.

Example sentences

  1. According to the CAP theorem, during a partition this system prefers availability over consistency.

  2. The interviewer asked me how the CAP theorem applies to our chat service.

Common collocations

  • CAP theorem
  • partition tolerance
  • consistency vs availability
  • CP system
  • AP system
  • 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.
  • NoSQLA broad group of databases that do not use the classic table-and-SQL model, storing data as documents, key-value pairs, wide columns or graphs instead.
  • ACIDAtomicity, Consistency, Isolation, Durability: the four guarantees that make database transactions reliable even with errors, crashes and many users at once.
  • replicationKeeping copies of the same database on several servers by sending every change from one server to the others, for safety and to share the load.

This word in other fields

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

More terms: Databases and Persistence

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