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Databases & SQL vocabulary · Indexes and Query Performance

Cache

Meaning in databases & SQL, with examples

/kæʃ/nounCommon term

In databases & SQL, cache means: A fast storage layer that keeps copies of frequently used data or query results so that they can be returned without asking the database again.

In Turkish: önbellek, cache

How it is used

Can sit in the application (Redis, Memcached) or inside the database itself (the buffer pool in MySQL, shared_buffers in PostgreSQL). Key phrases: cache hit, cache miss, warm cache, cold cache and cache invalidation, which means removing stale data when the source changes.

Example sentences

  1. We cache the product list for five minutes, so the database gets far fewer queries.

  2. The first run is slow because the cache is cold.

Common collocations

  • cache hit
  • cache miss
  • cache invalidation
  • clear the cache
  • warm cache
  • in-memory databaseA database that keeps its data mainly in RAM rather than on disk, so reads and writes are extremely fast.
  • key-value storeThe simplest kind of NoSQL database, which saves each value under a unique key and finds it again very quickly by that key.
  • query tuningThe work of making slow queries faster by studying their execution plans and then adding indexes, rewriting SQL or changing database settings.
  • slow queryA query that takes longer than an agreed limit to finish, slowing down the application and using up database resources.

This word in other fields

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

More terms: Indexes and Query Performance

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