# ADR-004 — PostgreSQL search before semantic infrastructure

## Status

Accepted

## Context

The library requires fast title, tag, category and intent search with filters. A vector database adds operational complexity and less explainable ranking.

## Decision

Use PostgreSQL full-text search plus structured filters and optional trigram matching. Add semantic search only after measured unmet discovery needs.

## Consequences

- one datastore and simple self-hosting;
- explainable matching;
- adequate scale for initial catalog and private content;
- synonyms and curated intent terms need content governance;
- future embedding index remains possible behind a search port.