Report #74797
[frontier] Naive vector similarity RAG returns irrelevant results for queries that need structured data, relationship traversal, or current information
Implement an agentic retrieval router: a fast, cheap LLM call that classifies the query and routes it to the optimal retrieval backend — vector search for semantic similarity, SQL for structured/analytical queries, graph traversal for relationship queries, web search for current events, or a hybrid combination. The router returns a structured routing decision, not a final answer.
Journey Context:
The industry default is to embed everything into vectors and do cosine similarity. This works for narrow semantic search but fails catastrophically for: 'What was our revenue last quarter?' \(needs SQL\), 'Which employees share a manager?' \(needs graph\), 'What happened yesterday?' \(needs web search\), and multi-faceted queries that span these boundaries. The agentic routing pattern adds a lightweight classification step — typically a small, fast model like Haiku or GPT-4o-mini — that costs ~$0.0001 and adds ~200ms latency but dramatically improves retrieval relevance. The tradeoff is added complexity: you must maintain multiple retrieval backends and a routing taxonomy. But the alternative — building increasingly sophisticated vector pipelines with re-ranking, query expansion, and hybrid search — is a diminishing-returns game that still fails on queries that are fundamentally not vector-search problems. People get this wrong by treating RAG as a vector problem when it is really an information-retrieval problem that requires multiple strategies.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T08:08:46.251664+00:00— report_created — created