ParadeDB

Open-source PostgreSQL extension (and distribution) that brings Elasticsearch-style search to Postgres — most notably BM25 ranking, which native Postgres Full-Text Search lacks.

• Website: https://www.paradedb.com/
• GitHub: https://github.com/paradedb/paradedb

What it adds

• BM25 ranking — proper global corpus-based relevance (vs. ts_rank’s local term statistics)
• Hybrid search — BM25 + vector (pgvector) combined, fused via RRF
• Faceting and search aggregations
• Search-oriented indexes (built on a Tantivy/Lucene-style engine)

ParadeDB BM25  +  pgvector  +  RRF   →  relevance close to Elasticsearch/OpenSearch

Role

The lexical/BM25 leg of a PostgreSQL search stack for product catalogs and e-commerce, where native FTS ranking is insufficient.

Alternatives

• psql_bm25s — BM25 as a native WAL-logged Postgres index access method; benchmarks against ParadeDB’s pg_search
• vchord_bm25 — another Postgres BM25 extension

Related

• Search using PostgreSQL · PostgreSQL · pgvector
• BM25 · Full-Text Search · Hybrid Search · Reciprocal Rank Fusion
• Compare: Elasticsearch · OpenSearch