RING: Retrieval-Internalized Generation for Continual Large-Scale Knowledge Injection

Shicheng Xu, Liang Pang, Liyi Chen, Zihao Wei, Jingcheng Deng, Yan Gao, Yi Wu, Yao Hu, Huawei Shen, Xueqi Cheng


Abstract
Retrieval-augmented generation (RAG) improves factuality but adds latency and engineering overhead at serving time. We propose RING (Retrieval-Internalized Generation), a holistic paradigm spanning both architecture and training that injects large-scale external knowledge into a Mixture-of-Memory Experts and learns parametric search over this internal memory via reinforcement learning, removing the external retriever entirely. Training proceeds in three stages: continued pre-training injects new corpora into a Knowledge Expert via our novel Dual Causal Attention; supervised fine-tuning teaches a “search-then-answer” pattern; and reinforcement learning with hierarchical rewards optimizes the routing-and-search policy over the parametric memory. Unlike prior parametric injection methods that pair internal memory with a fixed or rule-based retriever, RING learns its retrieval policy directly from task signals. We further frame RING theoretically as a search-free approximation to the classical RAG objective. To evaluate large-scale injection of genuinely new knowledge without test-time leakage, we further construct News-2025, a benchmark built from news strictly post-dating the base LLM’s pretraining cutoff. RING matches or surpasses both search-based RAG and parametric injection baselines in accuracy and efficiency.
Anthology ID:
2026.findings-emnlp.1940
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
41365–41381
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URL:
https://aclanthology.org/2026.findings-emnlp.1940/
DOI:
Bibkey:
Cite (ACL):
Shicheng Xu, Liang Pang, Liyi Chen, Zihao Wei, Jingcheng Deng, Yan Gao, Yi Wu, Yao Hu, Huawei Shen, and Xueqi Cheng. 2026. RING: Retrieval-Internalized Generation for Continual Large-Scale Knowledge Injection. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 41365–41381, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
RING: Retrieval-Internalized Generation for Continual Large-Scale Knowledge Injection (Xu et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1940.pdf