Search engine for PostgreSQL¶

atlas.search-postgres is the engine adapter that stores the search index in the same PostgreSQL database as the rest of Atlas, so enabling search adds no service. It only registers an engine; with no search plugin selected nothing uses it.

Purpose¶

It indexes documents into one table with a stored full-text vector and a GIN index. Title matches outrank body matches. Queries use PostgreSQL plain parsing, so every term is required and query-syntax characters are treated as plain text.

Dependencies¶

PostgreSQL and atlas.search. The adapter itself does not import the search plugin.

Enablement and configuration¶

Select it in the manifest next to atlas.search; with only one engine selected it is used automatically. Choosing between several engines and the engine setting are in Enable and operate search.

simple does no stemming or stop-word removal and works for any language, at the cost of matching exact word forms. Other configurations stem for one language only. Vectors are built at index time, so after changing the setting run python manage.py reindex. A name that is not a configuration known to the database makes indexing and queries fail.

Permissions¶

Not applicable: the adapter holds no per-user data and authorization is done by sources. It adds no permissions.

API surface¶

Not applicable: no routes. Its tables are described in the Search index schema.

Operations¶

replace_all deletes and refills the table in one transaction, so readers see the old index until commit and a failure rolls back. It uses DELETE rather than TRUNCATE to avoid blocking concurrent queries. Health reports the stored document count, which lets the search plugin rebuild an empty index at scheduler start. Capacity grows with the text indexed (bodies are bounded to 100 000 characters by default).

Extension surface¶

It is the reference for Write a search engine and runs the engine conformance suite in its own tests. It reports highlights=False, so snippets are built by core.

Limitations¶

• No typo tolerance; stemming only through a language-specific textSearchConfig. For typo tolerance see Run search on Meilisearch.
• Ranking is PostgreSQL ts_rank; relevance can differ from other engines.
• The index shares the database with Atlas data, so very large indexes compete with it for resources.

Compatibility¶

Version 0.1.0, atlas core >=0.1 <1.

Troubleshooting¶

A failing engine shows as engineHealthy: false in the status endpoint, and search answers 503. Check database connectivity and the engineDetail administrators see. After a language change, run reindex. See Enable and operate search.