Constraint Query Languages

这个项目探讨了在数据库应用程序中约束编程语言的开发和使用。约束查询语言（或cql）适用于许多特定于领域的领域，例如空间数据库，因为它们的基本数据类型泛化了关系元组数据类型，并且更接近应用程序语义，例如，对于空间数据库，这些泛化元组是凸空间点集。最重要的是，在设计cql时，可以通过现有的多维搜索数据结构支持对大型广义元组集的I/ o高效访问。本项目是对cql的原理和实践的调查。这些原则包括：各种类型的线性和非线性约束的表达能力；结合约束和对象的微积分/代数语言设计约束方案的优化；以及索引大量约束条件的数据结构。实践包括开发持久性约束语言的原型，并在三个具体应用领域对其进行评估：设计数据库中的实体建模；空间数据库中的地图叠加；在科学数据库中进行子序列匹配。约束查询语言将是下一代声明性数据库接口的关键组件，因为它们以一种有效的方式捕获特定于领域的语义，并且它们的成功实现将是当前关系和面向对象数据库技术的重要扩展

This project explores the development and use of constraint programming languages in database applications. Constraint Query Languages (or CQLs) are applicable to many domain-specific areas, such as spatial databases, because their basic data type generalizes the relational tuple data type and is closer to the application semantics, e.g., for spatial databases these generalized tuples are convex spatial point sets . Most importantly, CQLs are designed so that I/O-efficient access to large sets of generalized tuples can be supported through existing multi-dimensional searching data structures. This project is an investigation of both the principles and the practice of CQLs. The principles include: the expressive power of various classesof constraints both linear and nonlinear; the design of calculus/algebra languages combining constraints and objects; the optimization of constraint programs; and the data structures for indexing very large sets of constraints. The practice involves developing prototypes of persistent constraint languages and evaluating them in three concrete application areas: solid modeling in design databases; map overlays in spatial databases; and subsequence matching in scientific databases. Constraint Query Languages will be key components of the next generation of declarative database interfaces, because they capture domain-specific semantics in an efficient fashion, and their successful implementation will be a significant extension of the current relational and object- oriented database technologies