One Retrieval to Cover Them All: Co-occurrence-Aware Knowledge Base Reorganization for Session-Level RAG

Shivam Ratnakar, Yixuan Zhu, Cecilia Cheng, Chaya Vijayakumar


Abstract
RAG systems retrieve documents optimized for answering *one query at a time*. Yet enterprise users arrive with *sessions*, that is, coherent episodes of related questions that span semantically distant parts of the knowledge base. We show that a single retrieval call over a standard knowledge base covers only 41% of a user’s session-level information need. To close this gap, we reorganize the KB offline using co-occurrence-aware clustering and expand retrieval candidates through cluster neighborhoods at query time. On WixQA (6,221 enterprise support articles), our method raises single-query session coverage to 58% (+17% absolute; 95% CI: [14.1, 20.4]), reduces retrieval calls to 70% coverage by 34%, and compresses the KB to 20% of its original size, all consistently across four embedding models and six functional domains. We argue that session-level coverage, not single-query recall, should be the primary metric for enterprise RAG evaluation.
Anthology ID:
2026.knowfm-1.14
Volume:
Proceedings of the 4th Workshop on Towards Knowledgeable Foundation Models (KnowFM 2026)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Canyu Chen, Yuji Zhang, Zoey Sha Li, Zihan Wang, Qineng Wang, Jinyan Su, Priyanka Kargupta, Sara Vera Marjanović, Jeff Z. Pan, Mohit Bansal, Isabelle Augenstein, Jiawei Han, Heng Ji, Manling Li
Venues:
KnowFM | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
173–182
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.knowfm-1.14/
DOI:
Bibkey:
Cite (ACL):
Shivam Ratnakar, Yixuan Zhu, Cecilia Cheng, and Chaya Vijayakumar. 2026. One Retrieval to Cover Them All: Co-occurrence-Aware Knowledge Base Reorganization for Session-Level RAG. In Proceedings of the 4th Workshop on Towards Knowledgeable Foundation Models (KnowFM 2026), pages 173–182, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
One Retrieval to Cover Them All: Co-occurrence-Aware Knowledge Base Reorganization for Session-Level RAG (Ratnakar et al., KnowFM 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.knowfm-1.14.pdf