Hybrid Search: Combining pgvector with Full-Text Search

Hybrid search combines vector similarity and keyword-based full-text search using Reciprocal Rank Fusion (RRF). Run vector search using pgvector's HNSW index, run full-text search using tsvector and GIN indexes, combine using RRF where score = 1/(rank + k) with k=50, sum scores across methods and sort. Hybrid search improves recall by 15-25% compared to vector-only search.