Research into the Design and Implementation of Logical Data base Languages

新一代数据库应用程序，如设计数据库和科学数据库，以及集成的、不同种类的数据库，需要更强大的查询语言，能够支持声明性编程、即席查询、复杂对象和传统DB语言中找不到的其他功能。胶水/钉子语言第一次以一种语言提供了所有这些功能。它由一种“半说明性”语言GLUE和钉子组成，GLUE本质上是由常规序列、过程和模块连接的逻辑规则，它是GLUE的一个完全说明性的“视图工具”。为了使语言高效，必须使用某些优化技术，如“魔术集”和“常规递归优化”，并且必须对它们进行扩展以处理某些其他功能。这些包括子目标中的否定，遵循良好的语义，聚集(例如，总和，平均值)，以及支持集合和其他面向对象能力的二阶逻辑。

The new generation of database applications, such as design databases and scientific databases, and integrated, heterogeneous databases, requires more powerful query languages, able to support declarative programming, ad-hoc queries, complex objects, and other features not found in conventional DB languages. The GLUE/NAIL language provides, for the first time, all these capabilities in one language. It consists of a "semideclarative" language, GLUE, which is essentially logical rules connected by conventional sequencing, procedures, and modules, and NAIL, a completely declarative "view facility" for GLUE. To make the language efficient, certain optimization techniques, such as "magic sets" and "regular recursion optimization" must be used, and they must be extended to handle certain other features. These include negation in subgoals, following the well-founded semantics, aggregation (e.g., sum, avg.), and second-order logic to support sets and other object-oriented capabilities.