Strategy for processing multivariable queries in the database management system INGRES is considered. The general procedure is to decompose the query into a sequence of one-variable queries by alternating between (a) reduction: breaking off components of the query which are joined to it by a single variable, and (b) tuple substitution: substituting for one of the variables a tuple at a time. Algorithms for reduction and for choosing the variable to be substituted are given. In most cases the latter decision depends on estimation of costs; heuristic procedures for making such estimates are outlined.

In this paper a Document Base Management System is proposed that incorporates conventional database and hypertext ideas into a document database. The Document Base operates as a server, users access the database through different application programs. The query language which applications use to retrieve documents is described.

This paper describes the design and proposed implementation of a shared object hierarchy. The object hierarchy is stored in a relational database and objects referenced by an application program are cached in the program's address space. The paper describes the database representation for the object hierarchy and the use of POSTGRES, a next-generation relational database management system, to implement object referencing efficiently. The shared object hierarchy system will be used to implement OBJFADS, an object-oriented programming environment for interactive multimedia database applications, that will be the programming interface to POSTGRES. 1. Introduction Object-oriented programming has received much attention recently as a new way to develop and structure programs [GoR83, StB86]. This new programming paradigm, when coupled with a sophisticated interactive programming environment executing on a workstation with a bit-mapped display and mouse, improves programmer productivity and...