Yoshio Izumida

An object-oriented database system Jasmine: implementation, application, and extension

We have devised an object oriented DBMS called Jasmine for advanced applications. The paper describes the implementation, application and extension of Jasmine in detail. We focus on the impact of the design of its object oriented model and language on database implementation technology. We describe what part of traditional relational database technology we extend to handle object oriented features such as object identifiers, complex objects, class hierarchies, and methods. We introduce nested relations to efficiently store and access clustered complex objects. We use hash based methods to efficiently access nonclustered complex objects. We provide user defined functions directly evaluated on page buffers to efficiently process method invocation. We devise object oriented optimization of queries including class hierarchies, complex objects, and method invocation. We incorporate dedicated object buffering to allow efficient access to objects through object identifiers. We also describe nontrivial applications of Jasmine and discuss the validity of object oriented databases. We focus on a constraint management facility, which can be implemented by taking advantage of the extensibility of Jasmine. The facility includes constraint rules, called design goals, for automatic database population required by engineering applications. Finally, we describe a view facility for schema integration also needed by engineering applications in distributed environments. We focus on how we extend Jasmine to implement the facility.

A knowledge-based approach to design a portable natural language interface to database systems

This paper presents a knowledge-based approach to design a portable natural language interface to database systems, called KID (Knowledge-based Interface to Database systems). To free the user from the need to know about query languages and databases, and to allow the user to access databases in natural language, KID incorporates a knowledge base called the world model (WM), which contains a domain model, linguistic knowledge, and database mapping knowledge. To transport KID to a new domain, the user has only to build a new WM for the domain; the WM is easy for the user to define and understand. KIDs processing of the users query using the WM is transparent enough to the user to enable easy debugging of the WM. Encapsulating all the domain-specific knowledge into the WM makes KID portable. This paper discusses the WM design and KIDs knowledge-based processing of a query using the WM.

A natural language interface using a world model

Databases are nowadays used by varied and diverse users, many of whom are unfamiliar with the workings of a computer, but who, nevertheless, want to use those databases more easily. Rising to meet this demand, authors are developing a Japanese language interface, called KID, as a database front-end system. KID incorporates a world model representing application and database knowledge to help make databases easier to use. KID has the following features: (1) parser extendability and robustness, (2) independence from the application domain, (3) ease of knowledge editing, (4) independence from the database. This paper focuses on the first three features. KID has already been applied to the fields of housing, sales, and drug testing, thus confirming its transportability and practicality.