rails-search

Rails Search

Three tiers. Use the cheapest one that solves the problem. Most Rails apps never need Elasticsearch — Postgres + pg_search gets you to millions of rows with good UX. AI agents reach for ES by default; this skill pushes back.

The opinion

Default: pg_search with PostgreSQL tsvector + pg_trgm. Step up to Meilisearch when you need typo tolerance, autocomplete, and faceted UX. Reach for Elasticsearch / OpenSearch only when you genuinely need clustered, sharded, analytics-grade search at billion-row scale. Use searchkick as a Rails-idiomatic wrapper around either Elasticsearch or OpenSearch. Always index in the background, never inline.

Why this order:

• pg_search uses your existing database. No new infra. No sync drift.
• Meilisearch is a single-binary Rust server. Smaller than ES, sub-50ms queries, typo tolerance built-in.
• ES/OpenSearch is the right tool at scale but operationally expensive — cluster management, JVM tuning, mapping migrations.

Tier 1: pg_search (default)

Setup

# Gemfile
gem "pg_search"

# db/migrate/...
class AddPgTrgm < ActiveRecord::Migration[8.0]
  def change
    enable_extension "pg_trgm"  # for fuzzy / similarity
  end
end

Pattern 1: Per-model search

class Post < ApplicationRecord
  include PgSearch::Model

  pg_search_scope :search_full_text,
    against: { title: "A", body: "B" },   # weights — A is highest
    using: {
      tsearch: { prefix: true, dictionary: "english" },
      trigram: { threshold: 0.3 }
    }
end

Post.search_full_text("rails search")
# → ranked posts matching either by tsvector or trigram similarity

against: { title: "A", body: "B" } — Postgres ts_rank weights. A > B > C > D. Title matches rank higher than body matches.

Pattern 2: Multi-search across models

class Post < ApplicationRecord
  include PgSearch::Model
  multisearchable against: [:title, :body]
end

class User < ApplicationRecord
  include PgSearch::Model
  multisearchable against: [:name, :bio]
end

PgSearch.multisearch("alice")
# → ActiveRecord::Relation of PgSearch::Document
# Each document has searchable_type ("Post" or "User") and searchable_id.