Tabela hash

Armazenamento chave-valor com busca O(1) via função hash.

A hash table (or hash map) is a structure that can map keys to values. A hash table uses a hash [function](/pt/terms/hash-function) to compute an index into an array of buckets or slots, from which the desired value can be found. In an ideal case, the hash function will assign each key to a unique bucket, but most hash table designs employ some form of collision resolution.

        graph LR
  Center["Tabela hash"]:::main
  Rel_index_database["index-database"]:::related -.-> Center
  click Rel_index_database "/terms/index-database"
  Rel_relational_database["relational-database"]:::related -.-> Center
  click Rel_relational_database "/terms/relational-database"
  Rel_object["object"]:::related -.-> Center
  click Rel_object "/terms/object"
  classDef main fill:#7c3aed,stroke:#8b5cf6,stroke-width:2px,color:white,font-weight:bold,rx:5,ry:5;
  classDef pre fill:#0f172a,stroke:#3b82f6,color:#94a3b8,rx:5,ry:5;
  classDef child fill:#0f172a,stroke:#10b981,color:#94a3b8,rx:5,ry:5;
  classDef related fill:#0f172a,stroke:#8b5cf6,stroke-dasharray: 5 5,color:#94a3b8,rx:5,ry:5;
  linkStyle default stroke:#4b5563,stroke-width:2px;

      

🧠 Teste de conhecimento

1 / 1

🧒 Explique como se eu tivesse 5 anos

Imagine uma chapelaria. Você entrega seu casaco e recebe um número. Com o número, acham seu casaco direto. Tabelas [hash](/pt/terms/hash) calculam o 'número' a partir da sua chave!

🤓 Expert Deep Dive

Hashing perfeito. Cuckoo hashing. Robin Hood hashing. Consistent hashing para caches distribuídos. Filtros de Bloom.

📚 Fontes