If the data is this large then why not ask the llm to build a query
latency is often the reason, distilling interactions into significantly better retrieval is the second.
My case:
With a very large dataset of totally unnormalized data, semantic folding is a silver bullet.
That's more-or-less what RAG is; a tool to surface relevant data so that AI can make informed decisions. Efficient retrieval is important so that AI doesn't need to ingest the whole corpus for each query.