MOD

Requirements for future data base systems are developed from the perspective of the user of a networked workstation who naturally deals with compound objects. Objects considered include full text, diagrams, maps, sound recordings, images from film and ...

The future of computer aided design is in object oriented programming. If the database community hopes to participate in this future, it must reexamine some basic assumptions about the architecture of database systems. Database system functionality can ...

Query optimizers of future database management systems are likely to face large access plan spaces in their task. Exhaustively searching such access plan spaces is unacceptable. We propose a query optimization algorithm based on simulated annealing, ...

Current methods of evaluating nested queries in the SQL language can be inefficient in a variety of query and data base contexts. Previous research in the area of nested query optimization which sought methods of reducing evaluation costs is summarized, ...

We represent a set of possible worlds using an incomplete information database. The representation techniques that we study form a hierarchy, which generalizes relations of constants. This hierarchy ranges from the very simple Codd-table, (i e , a ...

The problem considered is that of implementing recursive queries, expressed in a logic-based language, by efficient fixpoint computations. In particular, the situation is studied where the initial bindings in the recursive predicate can be used to ...

We propose a technique based on Petri Nets formalism to model logic queries in deductive databases. The model is called PNLP (Petri Net model for Logic Programs), and it has a simple formal description and a graphical representation. The PNLP model ...

Redundancy may exist in the processing of recursive database queries at four different levels precompilation level, iteration level, tuple processing level and file accessing level. Techniques for reducing redundant work at each level are studied. In ...

Increased interest in using workstations and small processors for distributed transaction processing raises the question of how to implement the logs needed for transaction recovery. Although logs can be implemented with data written to duplexed disks ...

The evolutionary trend toward a database-driven public communications network has motivated research into database architectures capable of executing thousands of transactions per second. In this paper we introduce the Datacycle architecture, an attempt ...

With memory prices dropping and memory sizes increasing accordingly, a number of researchers are addressing the problem of designing high-performance database systems for managing memory-resident data. In this paper we address the recovery problem in ...

The features of a compiler for the Taxis design language are described and discussed. Taxis offers an entity-based framework for designing interactive information systems and supports generalisation, classification and aggregation as abstraction ...

The connection between semantic database models and the relational model is formally investigated using the Iris Data Model, which has been implemented using relational database techniques. The results focus on properties of relational schemas that are ...

We develop new algorithms for the design of non first normal form relational databases that are in nested normal form. Previously, a set of given multivalued dependencies and those multivalued dependencies implied by given functional dependencies were ...

This paper presents the design and an initial performance evaluation of the query optimizer generator designed for the EXODUS extensible database system. Algebraic transformation rules are translated into an executable query optimizer, which transforms ...

The query optimizer is an important system component of a relational database management system (DBMS). It is the responsibility of this component to translate the user-submitted query - usually written in a non-procedural language - into an efficient ...

This paper describes a scheme to utilize semantic integrity constraints in optimizing a user specified query. The scheme uses a graph theoretic approach to identify redundant join clauses and redundant restriction clauses specified in a user query. An ...

The multi-layered architecture of the DArmStadt Data Base System (DASDBS) for advanced applications is introduced DASDBS is conceived as a family of application-specific database systems on top of a common database kernel system. The main design problem ...

The goal of the EXODUS extensible DBMS project is to enable the rapid development of a wide spectrum of high-performance, application-specific database systems EXODUS provides certain kernel facilities for use by all applications and a set of tools to ...

A database management system architecture is described that facilitates the implementation of data management extensions for relational database systems. The architecture defines two classes of data management extensions alternative ways of storing ...

In a voting-based algorithm, a replicated file can be updated in a partition if it contains a majority of copies. In this paper, we propose an extension of this scheme which permits a file to be updated in a partition provided it contains a majority of ...

The concept of nested transactions offers more decomposable execution units and finer grained control over recovery and concurrency as compared to 'flat' transactions. To exploit these advantages, especially transaction recovery has to be refined and ...

Long lived transactions (LLTs) hold on to database resources for relatively long periods of time, significantly delaying the termination of shorter and more common transactions. To alleviate these problems we propose the notion of a saga. A LLT is a ...

A new multi-dimensional file structure has been developed in the course of a project to devise ways of improving the support for interactive queries to database and knowledge bases. Christened the 'BANG' file - a Balanced And Nested Grid - the new ...

A new method termed population analysis is presented for approximating the distribution of node occupancies in hierarchical data structures which store a variable number of geometric data items per node. The basic idea is to describe a dynamic data ...

We examine an extended relational database system which supports database procedures as full fledged objects. In particular, we focus on the problems of query processing and efficient support for database procedures. First, a variation to the original ...

ROSE is an experimental database system for CAD/CAM applications that organizes a database into entries and relationships. The data model of ROSE is an extension of the relational model and the data manipulation language is an extension of the ...

One of the most promising approaches to database support of engineering applications is the concept of object-oriented database management. Object-orientation is usually approached from either a behavioral or structural viewpoint. The former emphasizes ...

Object-oriented programming is well-suited to such data-intensive application domains as CAD/CAM, AI, and OIS (office information systems) with multimedia documents. At MCC we have built a prototype object-oriented database system, called ORION. It adds ...

We define a language G for querying data represented as a labeled graph G. By considering G as a relation, this graphical query language can be viewed as a relational query language, and its expressive power can be compared to that of other relational ...