Collaborative Research: The REVELATION Project: Query Processing in Behavioral Object-Oriented Databases

正在开发许多新的数据管理系统， 具有高级数据管理要求的应用程序，例如 扩展的关系模型、持久化编程语言和 面向对象的数据库这样的系统增强了语义 表现力，但它们必须提供良好的性能才能可行 商业技术。一个特别需要改进的领域 性能是查询处理，其中新的建模功能， 封装、类型层次结构、复杂值和对象 同一性使得传统集合处理方法变得困难， 无效应用。启示录项目的总体目标 是扩展查询处理以解决和利用这些新 所有级别的查询处理的建模扩展， 架构管理，通过优化和物理规划， 运行时支持。为了封装，结合了Revealer， 可以访问类型实现的受信任系统组件。 由于亚型分型和 多态性由一个注释器处理， schema定义。复杂的价值观和身份得到解决 都是在逻辑代数层面上， 与有序结构，如序列和数组，并在 物理水平与新的运营商，如一个组装复杂的 对象本项目将构建一个原型查询处理器， 利用现有的软件技术，如火山 优化器生成器和火山查询评估系统。

Many new data management systems are being developed to support applications with advanced data management requirements, such as extended relational models, persistent programming languages and object-oriented databases. Such systems enhance semantic expressiveness, but they must offer good performance to be viable commercial technologies. An area particularly needful of improved performance is query processing, where new modeling features such as encapsulation, type hierarchies, complex values and object identity make conventional set-processing methods difficult or ineffective to apply. The overall goal of the Revelation project is to expand query processing to address and exploit these new modeling extensions at all levels of query processing, from schema management, through optimization and physical planning, to runtime support. For encapsulation, a Revealer is incorporated, a trusted system component that can access type implementations. Heterogeneity in collections arising from subtyping and polymorphism is handled by an Annotater that reasons across schema definitions. Complex values and identity are addressed both at the logical algebra level, with new operations to deal with ordered structures such as sequences and arrays, and at the physical level with new operators such as one to assemble complex objects. This project will construct a prototype query processor, exploiting existing software technology such as the Volcano optimizer generator and the Volcano query evaluation system.