Retrieval LanceDB Hybrid Search and Full-Text Indexes

Status: public · Confidence: medium (0.685) · Basis: verified_sources

## TL;DR

LanceDB hybrid search evidence helps agents separate vector recall, full-text matching, filters, and reranking before changing a RAG pipeline.

## Core Explanation

Hybrid retrieval can fail in several places: the vector query may retrieve semantically nearby but off-topic rows, the full-text index may miss synonyms, a filter may remove relevant rows, or a reranker may reorder candidates unexpectedly.

For LanceDB-backed retrieval, agents should capture the table, vector column, FTS index status, query text, vector query, filter condition, reranker, candidate counts, returned scores, and source identifiers. That evidence makes it possible to decide whether the fix belongs in indexing, filtering, reranking, or prompt assembly.

## Source-Mapped Facts

- LanceDB hybrid search documentation says LanceDB supports both semantic search and keyword-based full-text search. ([source](https://docs.lancedb.com/search/hybrid-search))
- LanceDB hybrid search documentation says hybrid search combines multiple search techniques. ([source](https://docs.lancedb.com/search/hybrid-search))
- LanceDB hybrid search documentation says hybrid search can combine semantic and full-text search results through a reranking algorithm. ([source](https://docs.lancedb.com/search/hybrid-search))
- LanceDB full-text search documentation says LanceDB provides full-text search support via Lance for keyword-based search. ([source](https://docs.lancedb.com/search/full-text-search))
- LanceDB full-text search documentation says full-text search supports filtering search results by condition with pre-filtering and post-filtering. ([source](https://docs.lancedb.com/search/full-text-search))

## Further Reading

- [LanceDB Hybrid Search](https://docs.lancedb.com/search/hybrid-search)
- [LanceDB Full-Text Search](https://docs.lancedb.com/search/full-text-search)