Anatomy of a (Postgres) search engine

What it is

A clear, patient walkthrough of how full-text search actually works inside a database: inverted indexes, term dictionaries, postings lists, tokenizers, BM25 scoring, and how Postgres does each part. Written by Patrick Reynolds and Eric Ridge and published 22 September 2026. Free to read, no sign-up.

Why I recommend it

The best free explanation I have found of what a search engine is doing under the bonnet — useful even if you never touch a database, because it shows why a search box returns what it returns. It is published by PlanetScale, who sell hosted Postgres, so the closing pitch is theirs; the explanation itself stands on its own.

Topics

#postgres #databases #search #full-text-search #indexing #bm25 #engineering #how-it-works

Added Sep 22, 2026 · 0 opens