Fast Tuning the Index Construction Parameters of Proximity Graphs in Vector Databases
Wenyang Zhou, Jiadong Xie, Yingfan Liu, Zhihao Yin, Jeffrey Xu Yu, Hui Li, Zhangqian Mu, Xiaotian Qiao, Jiangtao Cui
TL;DR
FastPGT tackles the costly problem of tuning proximity-graph construction parameters for $k$-ANNS by enabling batch parameter recommendations and simultaneous construction of multiple PGs to exploit shared computations. It eliminates the RNG parameter $R$ from tuning, introduces a batch MOBO approach via $m$EHVI, and deploys efficient shared Search and Prune strategies (via $V_{\delta}$ caching and $mKANNS$/ $mPrune$) to dramatically reduce distance computations. The framework is model-agnostic and PG-agnostic, demonstrated to achieve up to $2.37\times$ speedups over the previous SOTA (VDTuner) while maintaining or improving Recall$@k$ and QPS across HNSW, NSG, and Vamana on real-world datasets. These contributions significantly accelerate practical tuning of PG indexes for vector databases and retrieval-augmented systems, enabling faster deployment of high-performance $k$-NN search pipelines.
Abstract
k-approximate nearest neighbor search (k-ANNS) in high-dimensional vector spaces is a fundamental problem across many fields. With the advent of vector databases and retrieval-augmented generation, k-ANNS has garnered increasing attention. Among existing methods, proximity graphs (PG) based approaches are the state-of-the-art (SOTA) methods. However, the construction parameters of PGs significantly impact their search performance. Before constructing a PG for a given dataset, it is essential to tune these parameters, which first recommends a set of promising parameters and then estimates the quality of each parameter by building the corresponding PG and then testing its k-ANNS performance. Given that the construction complexity of PGs is superlinear, building and evaluating graph indexes accounts for the primary cost of parameter tuning. Unfortunately, there is currently no method considered and optimized this process.In this paper, we introduce FastPGT, an efficient framework for tuning the PG construction parameters. FastPGT accelerates parameter estimation by building multiple PGs simultaneously, thereby reducing repeated computations. Moreover, we modify the SOTA tuning model to recommend multiple parameters at once, which can be efficiently estimated using our method of building multiple PGs simultaneously. Through extensive experiments on real-world datasets, we demonstrate that FastPGT achieves up to 2.37x speedup over the SOTA method VDTuner, without compromising tuning quality.
