Accelerating Generative Recommendation via Simple Categorical User Sequence Compression
Qijiong Liu, Lu Fan, Zhongzhou Liu, Xiaoyu Dong, Yuankai Luo, Guoyuan An, Nuo Chen, Wei Guo, Yong Liu, Xiao-Ming Wu
TL;DR
This work tackles the efficiency bottleneck of generative recommenders that model ultra-long user histories by introducing CAUSE, a simple categorical user sequence compression method. CAUSE partitions histories into a long-term component and a recent sequence, then compresses the history into $V$ history tokens by grouping items into item-category buckets and aggregating bucket representations, yielding input tokens that preserve past interests with far lower compute. The approach achieves up to $6\times$ reductions in computational cost and up to $39.14\%$ accuracy gains at comparable cost across two large datasets and backbone models, and it is model-agnostic, compatible with backbones like HSTU and GenRank. The authors also provide ablations and an open-source implementation, underscoring the method's practicality for real-world deployment of efficient generative recommendations.
Abstract
Although generative recommenders demonstrate improved performance with longer sequences, their real-time deployment is hindered by substantial computational costs. To address this challenge, we propose a simple yet effective method for compressing long-term user histories by leveraging inherent item categorical features, thereby preserving user interests while enhancing efficiency. Experiments on two large-scale datasets demonstrate that, compared to the influential HSTU model, our approach achieves up to a 6x reduction in computational cost and up to 39% higher accuracy at comparable cost (i.e., similar sequence length).
