rag

Perspectives · 9 min read · 2023-12-14

GraphRAG Is Useful When the Question Is About Relationships, Not Similarity

Vector retrieval is excellent when the answer lives near semantically similar text. Graph-oriented retrieval earns its cost when the answer depends on relationships, communities, or evidence spread across multiple parts of a corpus.

Perspectives · 9 min read · 2020-02-05

pgvector HNSW Can Return Fast Answers That Are Operationally Wrong

Approximate nearest-neighbor search is allowed to trade recall for speed. Add tenant or metadata filters after the ANN scan and a fast query can return too few candidates without being a database error.

PostgreSQL pgvector hnsw rag