Cardinality estimation with index-based progressive sampling and dynamic sample selection
摘要
Cardinality estimation is a fundamental and critical problem in query optimization for database management systems. Although sampling-based methods have been widely used in commercial databases for over a decade, their estimation results can be inaccurate when samples lack representativeness or when the distribution of query-related attributes is uneven. This paper proposes a method called Cardinality Estimation with Index-Based Progressive Sampling and Dynamic Sample Selection (PSDSS). Traditional sampling methods often lead to empty join results and high sampling overhead in multi-table joins. In contrast, PSDSS employs a dynamic sample selector to recommend suitable samples for queries, thereby improving sample quality and estimation accuracy. In cases of empty joins, PSDSS estimates intermediate results through index-based progressive sampling, focusing on high-quality regions based on query predicates. Experiments on five real-world datasets demonstrate that PSDSS achieves faster training speeds and nearly