Modern search systems use several large ranker models with transformer architectures. These models require large computational resources and are not suitable for usage on devices with limited computational resources. Knowledge distillation is a popular compression technique that can reduce the resource needs of such models, where a large teacher model transfers knowledge to a small student model. To drastically reduce memory requirements and energy consumption, we propose two extensions for a popular sentence-transformer distillation procedure: generation of an optimal size vocabulary and dimensionality reduction of the embedding dimension of teachers prior to distillation. We evaluate these extensions on two different types of ranker models. This results in extremely compressed student models whose analysis on a test dataset shows the significance and utility of our proposed extensions.

本篇研究提出了在两种不同类型的ranker模型上扩展句子转换蒸馏过程的两种方法，包括生成最优尺寸的词汇表和在蒸馏之前对教师的嵌入维数进行降维。结果表明，采用这些扩展技术的学生模型具有极大的压缩程度，而且在测试数据集上表现出高度的有效性和能用性。

句向量排序模型的极端压缩：在边缘设备上实现更快的推理、更长的电池续航和更少的存储