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Peter Buneman seminar Friday May 12, MIT
Date: Mon, 8 May 89 15:42:25 EDT
SEMINAR
DATE: Friday, May 12, 1989
TIME: 4:00 pm
PLACE: MIT 36-428
TYPES FOR PERSISTENT DATA
Peter Buneman
Department of Computer and Information Science
University of Pennsylvania
The inadequate expressive power of the relational data model for many
database representation tasks -- especially those that do not conform
to requirements of traditional data processing -- has led several
database systems developers to abandon relational databases and adopt
an alternative "object-oriented" approach to the representation of
data. But if we do this, must we necessarily sacrifice the the
high-level languages and the considerable implementation technology
that have been developed for relational databases? I shall argue that
if we take a more liberal attitude to what a relation is, we can
generalize relational languages, and even some of the ideas in
relational database design, to work for sets of objects.
A closely related problem is how we represent sets of objects as typed
values in a programming language. If we can find such a
representation, can types be checked statically, or must we we live
with the dangers of the kinds of run-time type checking that
characterizes many object-oriented languages? Some recent results
show that a new polymorphic type system that is intimately connected
with a type inference method not only allows static type checking, but
also has the obvious advantage that the programmer does not have to
declare the types for many of his programs! These ideas are embodied
in the experimental programming language Machiavelli, which is
currently being developed at the University of Pennsylvania.
This is joint work with Atsushi Ohori and Val Breazu-Tannen
Host: Boston SIGMOD chapter