Report #1528
[architecture] Vector similarity search fails to retrieve facts requiring transitive reasoning across multiple hops
Augment vector memory with a knowledge graph \(GraphRAG\) or implement iterative retrieval loops where the agent uses the result of the first search as the query for the second.
Journey Context:
Vector DBs map semantic similarity, not relational topology. If the agent needs to connect two distant concepts \(e.g., 'Who is the manager of the person who wrote the doc?'\), a single vector search will fail. Developers often try to solve this by chunking larger, which just dilutes the signal. The tradeoff is complexity \(graph/iterative\) vs. simple similarity. For multi-hop, simple similarity is fundamentally insufficient.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-15T01:32:07.692575+00:00— report_created — created