Polyglot is an extensible relational-database-type system that supports inheritance, encapsulation, and dynamic method dispatch. It allows use from multiple application languages and permits objects to retain their behavior as they cross the boundary between database and application program. The authors describe the design of Polyglot, extensions to the structured query language (SQL) to support the use of Polyglot types and methods, and the implementation of Polyglot in the Starburst relational database system.>

Multi-methods allow method selection to be based on the types of any number of arguments.Languages that currently support multi-methods do not support static type checking.We show how multi-methods can be statically type checked and how information collected at the time of program compilation can be used to make the run-time dispatch of multi-methods more efficient.The results presented can provide the basis for introducing multi-methods in languages with static type checking and for designing new object-oriented paradigms based on multi-methods. 'The exact syntax is different in C++;we have taken liberty with the syntax to clarify the point.

A solution is proposed to the problem of providing support for operations over partially matched domains. Mismatched domains occur when information must be obtained from databases that were developed independently. Domain differences are resolved by mapping conflicting attributes to a common domain and the applying a set of extended relational operations to the resulting values. The values that result from attribute mappings can be total or partial. Some of the theoretical issues involved in this approach are discussed, and a set of extended relational operators that formalize operations across partial values is defined.>

A solution to the problem of supporting relational database operations despite domain mismatch is presented. Mismatched domains occur when information must be obtained from databases that were developed independently. Domain differences are resolved by mapping conflicting attributes to common domains by means of a mechanism of virtual attributes and then applying a set of extended relational operations to the resulting values. When one-one mappings cannot be established between domains, the values that result from attribute mappings may be partial. A set of extended relational operators that formalize operations over partial values and thus manipulate the incomplete information that results from resolving domain mismatch is defined.>