论文标题
有关操作员级查询执行成本建模的注释
A Note On Operator-Level Query Execution Cost Modeling
论文作者
论文摘要
使用查询执行反馈的外部查询执行成本建模已在各种数据库应用程序中找到了其方式，例如入学控制和查询计划。现有技术一般分为两类，计划级成本建模和运营商级成本建模。在文献中已经显示，操作员级成本建模通常可以显着超过计划级成本建模。在本文中，我们从健壮性的角度研究了运营级成本建模。对于使用多种成本建模技术，我们解决了有关有限的执行反馈（对于某些操作员）和混合成本估算的实践中的两个主要挑战。我们提出了一个处理这些问题的框架，并对此框架进行了全面分析。我们进一步提供了一个案例研究，以在索引调整的背景下证明我们的框架的功效，这本身就是外部成本建模技术的新应用。
External query execution cost modeling using query execution feedback has found its way in various database applications such as admission control and query scheduling. Existing techniques in general fall into two categories, plan-level cost modeling and operator-level cost modeling. It has been shown in the literature that operator-level cost modeling can often significantly outperform plan-level cost modeling. In this paper, we study operator-level cost modeling from a robustness perspective. We address two main challenges in practice regarding limited execution feedback (for certain operators) and mixed cost estimates due to the use of multiple cost modeling techniques. We propose a framework that deals with these issues and present a comprehensive analysis of this framework. We further provide a case study to demonstrate the efficacy of our framework in the context of index tuning, which is itself a new application of external cost modeling techniques.
