Addressing the “Sandglass” Bottleneck in Residual Quantization Semantic Identifiers for Generative Search and Recommendation
The paper identifies a “sandglass” bottleneck in Residual Quantization Semantic Identifiers, where middle‑layer tokens dominate, causing sparse paths and long‑tail distributions that hurt e‑commerce search performance, and demonstrates that adaptive pruning of these tokens restores accuracy and efficiency better than removing the layer entirely.