Implementation of the nested relational algebra in Java

• Main Author: Hao, Biao.
• Other Authors: Merrett, Tim (advisor)
• Format: Others
• Language: en
• Published: McGill University 1998
• Subjects: Computer Science.
• Online Access: http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=20569

This thesis discusses the design and implementation of a database programming language that supports the relational algebra for nested relations with arbitrary but finite levels of nesting, and the domain algebra for nested attributes at any level of the nested hierarchy. Views, including recursive views, are also implemented. === Support for nested relations is accomplished by means of four mechanisms. The first is the introduction of new syntax for the declarations of nested attributes and relations, the initialization of nested relations, and for nested updates. The second is the integration of relational expressions into domain expressions so that relational operations can be applied to nested attributes. The third is the definition of order among relations so that relation-valued attributes are treated the same way as attributes of primitive type such as integer and string. The fourth is to use a set of flat relations which are linked to each other by surrogates, to model a nested relation. With these mechanisms, our implementation provides uniform syntax and notation for the relational algebra and the domain algebra of nested relations. === The Java programming language is used for the implementation. Therefore, it runs on any platform that supports the Java runtime environment.