MENTAL MODEL · M7590

Inverted Index

CreateHigh supportDesign Thinking

Included

Version 1.0.0 · Updated 2026-07-30

CORE DEFINITION

A mapping from words to lists of documents, rather than from documents to words, enabling extremely fast keyword searches. Scaffolding role: optimize storage structure for queries. Trade write efficiency for read efficiency—design data structures based on usage patterns.

SCAFFOLDING EFFECT

psychology

Reduce cognitive load

Optimize storage structure for queries. Trade write efficiency for read efficiency—design data structures based on usage patterns.

anchor

Anchor fast decisions

Traditional indexes map documents to their contained words; inverted indexes reverse this to map words to lists of document IDs (and positions). Queries only need to look up the word to obtain candidate document sets, avoiding scanning each document. Essentially, it trades space (extra index) for time (query speed) and optimizes the structure according to query patterns (read-heavy, write-light).

MINIMUM ACTION

In progress 0/5

Practice this model in one real situation:

Build the index: traverse documents, recording document IDs and positions for each word
For queries, directly locate the word and retrieve the document list, then perform intersection/union operations
Use compression (dictionary, posting lists) to reduce storage
Accept the cost of updating the index on writes
Adopt as needed in search engines, Elasticsearch, databases, etc.

Check to track your progress (stored locally)

Learning progress0%

account_treeGenealogyexpand_more

menu_bookReferencesexpand_more

Source support: Explicit

link
zh.wikipedia.orghttps://zh.wikipedia.org/wiki/%E5%80%92%E6%8E%92%E7%B4%A2%E5%BC%95ZH · Explicit
verified

RELATED MODELS