QCFuse: Query-Aware Cache Fusion via Compressed View for Efficient RAG Serving
On the map: Retrieval-augmented generation → Generation and context integration
Abstract (arXiv)
Retrieval-augmented generation (RAG) improves large language model (LLM) answer quality by grounding generation in external evidence, but processing retrieved contexts makes the prefill stage a dominant serving cost. RAG cache fusion reduces this cost by reusing precomputed key-value (KV) caches for retrieved chunks and selectively recomputing tokens under the current prompt. Existing selectors, however, face a dilemma between quality and efficiency: fast query-agnostic or final-layer query-to-context selectors can miss request-relevant evidence, whereas full-view query-aware selectors require broad context and layer visibility before recomputation and therefore stall the layer-wise cache-fusion pipeline. We present QCFuse, a compressed-view query-aware selector for RAG cache fusion. QCFuse uses chunk-anchor query probing to condition user-query states on compact per-chunk anchors and critical-layer profiling to identify recomputation tokens without all-layer inspection. We implement QCFuse in SGLang and evaluate it on four open-weight LLMs across six datasets. QCFuse reaches full-prefill-level quality. At matched quality, QCFuse achieves an average prefill-time speedup of 1.7x over full prefill and 1.5x over ProphetKV, the strongest quality-preserving baseline.
Key facts. Cited by 3 papers in the map (data through 14 Oct 2026). Placed in Generation and context integration, one of 15 directions in Retrieval-augmented generation. Builds on 46 of its 66 references that are in the map. First posted on arXiv 4 Jun 2026.
Builds on
46 of 66 references.
Closest ancestors · 3
Same direction, newest first
- 2023RECOMP: Improving Retrieval-Augmented LMs with Compression and Selective Augmentation6 Oct
- 2020Retrieval-Augmented Generation for Knowledge-Intensive NLP Tasks22 May
- 2020REALM: Retrieval-Augmented Language Model Pre-Training10 Feb
Other references · 43
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31 more
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Built on by
Citing papers per year: 2026: 3.
3 papers.
Similar, not cited
Close in wording, no citation either way
- 2026QCFuse: Query-Centric Cache Fusion for Efficient RAG Inference
- 2026From Prefix Cache to Fusion RAG Cache: Accelerating LLM Inference in Retrieval-Augmented Generation
- 2025Cache-Craft: Managing Chunk-Caches for Efficient Retrieval-Augmented Generation
- 2026Fine-Tuning a KV Cache Concatenation-Aware Model or Recomputing KV Caches? Why Not Both?
- 2026ProphetKV: User-Query-Driven Selective Recomputation for Efficient KV Cache Reuse in Retrieval-Augmented Generation
- 2024RazorAttention: Efficient KV Cache Compression Through Retrieval Heads
- 2025CacheClip: Accelerating RAG with Effective KV Cache Reuse
- 2024Toward Optimal Search and Retrieval for RAG