HybridRAG: A Fusion of Graph and Vector Retrieval - Mitesh Patel, NVIDIA
Jul 22, 2025 · 20:24
Mitesh Patel, Developer Advocate Manager at NVIDIA, presents HybridRAG, a fusion of knowledge graph-based GraphRAG and vector-based VectorRAG for improved question-answering from complex texts. He emphasizes that ontology engineering consumes 80% of development time and is critical for accurate triplet extraction, where fine-tuning LLaMA 3.1 with LoRA boosted triplet accuracy from 71% to 87% on 100 documents. Patel also highlights retrieval strategies like multi-hop graph traversal, which provides richer context but increases latency, and recommends QGraph acceleration via Networx to reduce latency. For evaluation, he suggests RAGAS for end-to-end pipeline metrics and the LLaMA-Nimotron reward model for response quality. Ultimately, he advises using GraphRAG when data has inherent structure or complex relationships, but notes it is compute-heavy, so the choice between GraphRAG, semantic RAG, or hybrid depends on the use case.
