RIA: Towards A Generic Visual Query Language for Object- Oriented Systems

点击翻译按钮获取中文摘要

RIA: Towards a Generic Visual Query Language with Formal Basis for Object-Oriented Databases This is the first year funding of a three-year continuing award. Object-oriented databases have been recognized as very useful for advanced non-traditional applications such as design, planning, scheduling and geographic applications. Recently a number of object-oriented data models have been developed. To facilitate easy querying in these disparate models, a number of visual query languages have been proposed. This project identifies the basic constructs required for visual querying in object-oriented applications, and uses them to design and implement a generic visual query language. This language extends gracefully from relational and nested models to disparate object-oriented models (extendibility). It uses as few basic language constructs as necessary, while at the same time is versatile enough to encode specialized query-features of diverse object-oriented languages (few but powerful core language constructs). Furthermore, such encodings are user-friendly. The generic language has strong theoretical foundations: (1) enabling formal semantics, with proper consideration for safety, negation, etc., and a formal basis for measuring expressivity and complexity; and (2) proving minimality of the constructs and showing how they simulate other useful query-constructs, etc. Such a generic language will provide a uniform front-end to users of diverse object-oriented models and applications, and will play an important role if developed as a server (analogous to SQL-servers) in a client- server environment.