@book{9ecc3cd69ee8421cb4cc60e9971b0158,
title = "A Database Interface for Complex Objects",
abstract = "We describe a formal design for a logical query language using psi-terms as data structures to interact effectively and efficiently with a relational database. The structure of psi-terms provides an adequate representation for so-called complex objects. They generalize conventional terms used in logic programming: they are typed attributed structures, ordered thanks to a subtype ordering. Unification of psi-terms is an effective means for integrating multiple inheritance and partial information into a deduction process. We define a compact database representation for psi-terms, representing part of the subtyping relation in the database as well. We describe a retrieval algorithm based on an abstract interpretation of the psi-term unification process and prove its formal correctness. This algorithm is efficient in that it incrementally retrieves only additional facts that are actually needed by a query, and never retrieves the same fact twice.",
keywords = "DB-OODB: OBJECT-ORIENTED DATABASES, DB-DDB: DEDUCTIVE DATABASES, Relational databases, Complex object, Abstract interpretation, Psi-terms, Information retrieval, Inheritance, Logical Query Languages, Deductive databases",
author = "Marcel Holsheimer and {de By}, {Rolf A.} and Hassan A{\"i}t-Kaci",
year = "1993",
month = mar,
language = "English",
series = "PRL Research Reports",
publisher = "Digital Equipment Corporation, Paris Research Laboratory",
number = "PRL-RR",
}