Bilevel Relations and Their Applications to Data Insights

Many data-insight analytic tasks in anomaly detection, metric attribution, and experimentation analysis can be modeled as searching in a large space of tables and finding important ones, where the notion of importance is defined in some adhoc manner. While various frameworks have been proposed (e.g., DIFF, VLDB 2019), a systematic and general treatment is lacking. This paper describes bilevel relations and operators. While a relation (i.e., table) models a set of tuples, a bilevel relation is a dictionary that explicitly models a set of tables, where each ``value'' table is identified by a ``key'' of a (region, features) pair, where region specifies key attributes of the table, and features specify columns of the table. Bilevel relational operators are BilevelRelation-to-BilevelRelation transformations and directly analyze a set of tables. Bilevel relations and operators provide higher level abstractions for creating and manipulating a set of tables, and are compatible with the classic relational algebra. Together, they allow us to construct bilevel queries, which can express succinctly a range of insight-analytical questions with ``search+eval'' character. We have implemented and deployed a query engine for bilevel queries as a service, which is a first of its kind. Bilevel queries pose a rich algorithm and system design space, such as query optimization and data format, in order to evaluate them efficiently. We describe our current designs and lessons, and report empirical evaluations. Bilevel queries have found many useful applications, and have attracted more than 30 internal teams to build data-insight applications with it.

可以将许多数据觉性检测，度量归因和实验分析中的分析任务建模为在较大的表格中搜索并找到重要的搜索，其中重要性的概念以某种方式定义了。尽管已经提出了各种框架（例如，Diff，VLDB 2019），但缺乏系统的一般治疗方法。本文描述了二线关系和操作员。虽然一个关系（即表）模型一组元组，但双重关系是一本词典，可以明确对一组表进行建模，其中每个表由一个``值''表识别为一个（区域，区域，''键'功能）对，区域指定表的关键属性，并指定表的列。二重性关系运算符是二链球化与二级联的转换，直接分析了一组表。二重关系和操作员提供了更高级别的抽象来创建和操纵一组表，并且与经典的关系代数兼容。它们共同使我们能够构建双重查询，这些查询可以用``搜索+eval''字符简洁地表达一系列洞察力分析问题。我们已经实施并部署了用于二重性查询的查询引擎作为服务，这是其中的第一个服务。 Bilevel查询构成了丰富的算法和系统设计空间，例如查询优化和数据格式，以便有效地评估它们。我们描述了我们当前的设计和课程，并报告经验评估。 Bilevel查询发现了许多有用的应用程序，并吸引了30多个内部团队来构建数据订婚应用程序。