long-context RAG sparse attention — Practical Guide to DSA, FAISS, and Cost‑Efficient Inference Intro Quick answer (one sentence): long-context RAG sparse attention reduces the quadratic attention cost of long-context retrieval-augmented generation by selecting a small top-k subset of context tokens (O(L·k) instead of O(L^2)), enabling RAG optimization and cost-efficient inference at tens to hundreds of […]
