Aging RAG stores may need freshness more than better embeddings
As a RAG store grows older and larger, it can collect many old pieces that look similar to newer information. Pure meaning-based search can then return that match the question well but are no longer correct. Testing found a point where results with freshness and past use beat ranking by meaning alone.
That point depended more on the store’s size and age than on the . In large stores, most lost recall came from stale content, not weak . Static recall@k tests can make live look better than it really is because real questions change over time.
The practical advice is to adjust freshness weight as the store grows, and to lower the score of replaced chunks instead of deleting them immediately. A mistaken stale-check can otherwise remove a real memory that is still useful.
Key points
- Large RAG stores can surface stale but convincing chunks.
- Freshness can beat pure meaning-based ranking after the store ages.
- Store size and age mattered more than the in this test.
- Static recall@k can overstate real-world .
- Lowering the score of replaced chunks is safer than hard-deleting them.