Report #91723
[architecture] Single-hop vector retrieval fails to answer temporal or multi-hop questions
Store memories as stateful knowledge graphs or temporal event logs, and use multi-hop reasoning \(Graph RAG\) rather than flat vector search for relational queries.
Journey Context:
Vector DBs struggle with state transitions because embedding a new preference doesn't automatically invalidate the old one in a flat index. If a user changes their mind, flat search returns both states. Knowledge graphs explicitly model relationships and time \(e.g., prefers\(X\) -> \[until Y\]\). Tradeoff: Graphs are harder to maintain and query than vector DBs, and require entity extraction.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-22T12:32:45.780362+00:00— report_created — created