Deductive Object-oriented Database Research Articles

PSE: An Object-Oriented Representation for Modeling and Managing Part-of Relationships

Part-of relationships are needed to model structures of composite objects. Especially, composite objects, known as physical assemblies, are very popular in several applications. The existing object-oriented representations of physical assemblies and query languages based on them have several disadvantages. For example, they suppose that the user knows the structure of a physical assembly completely. This is not a realistic requirement in those cases where a physical assembly consists of a huge number of parts. Likewise the user has in them to control traversals of physical assemblies, i.e. they have a low degree of declarativity. Further, they do not support intensional and combined extensional-intensional queries which would be necessary in an advanced manipulation of physical assemblies. We develop the PSE (Part-of Structure Element) representation for removing the above disadvantages. The PSE representation is a set theoretical and constructor-oriented representation for physical assemblies and it can be used in the implementation based on both the object-oriented and deductive object-oriented database (DOOD) paradigms.

Computational Music Representation Based on the Generative Theory of Tonal Music and the Deductive Object-Oriented Database

Computational Music Representation Based on the Generative Theory of Tonal Music and the Deductive Object-Oriented Database

Interactive Music Summarization Based on Generative Theory of Tonal Music

This paper presents an algorithm that checks for melodic similarity and a music summarization system called “Papipuun.” First, we developed a data structure for representing polyphony based on a time-span reduction in the generative theory of tonal music (GTTM) and the deductive object-oriented database (DOOD). A least upper bound operation is introduced to check the similarity of polyphonies represented in our method. Next, Papipuun performs quick listening in a manner similar to stylus skipping on a scratched record, but the skipping occurs correctly at punctuations of musical phrases, not arbitrarily. Papipuun can produce a music summary of good quality with a symbolic approach, reflecting the atmosphere of an entire piece through interaction with the user. In a pre-processing phase of Papipuun, a user analyzes an input piece by time-span reduction, using a dedicated tool called TS-Editor. For the real-time phase, the user interacts with the main system, Summarizer, to perform music summarization. The summarizer ascertains a piece structure by similarity checking. When the user identifies fragments to be skipped, Summarizer deletes them and concatenates the rest.

A logical foundation for deductive object-oriented databases

Over the past decade, a large number of deductive object-oriented database languages have been proposed. The earliest of these languages had few object-oriented features, and more and more features have systematically been incorporated in successive languages. However, a language with a clean logical semantics that naturally accounts for all the key object-oriented features, is still missing from the literature. This article takes us another step towards solving this problem. Two features that are currently missing are the encapsulation of rule-based methods in classes, and nonmonotonic structural and behavioral inheritance with overriding, conflict resolution and blocking. This article introduces the syntax of a language with these features. The language is restricted in the sense that we have omitted other object-oriented and deductive features that are now well understood, in order to make our contribution clearer. It then defines a class of databases, called well-defined databases , that have an intuitive meaning and develops a direct logical semantics for this class of databases. The semantics is based on the well-founded semantics from logic programming. The work presented in this article establishes a firm logical foundation for deductive object-oriented databases.

Building deductive object-oriented database systems in the ODMG era

Deductive object-oriented database systems (DOODs) have been a subject of intensive research for the last 13 years, with results embodied in several research prototypes and one commercial system produced so far [1]. However, despite the considerable number of systems available, there has been surprisingly little work on organising and analysing the several system architectures and query processing strategies that have been employed in the construction of DOODs. Furthermore, with the consolidation of the ODMG specification as a standard for object databases, it is important to assess which architectural approach is better suited for building DOODs considering the ODMG framework. This paper categorises several representative DOOD systems based on their architecture and query processing approach, and provides an analysis of the issues involved in building DOOD systems compliant with the ODMG standard.

Query language approach based on the deductive object-oriented database paradigm

The integration of data-oriented (structural), behavioral and deductive aspects is necessary in next generation information systems. The deductive object-oriented database paradigm offers a very promising starting point for the implementation of these kinds of information systems. So far in the context of this paradigm a big problem has been the lack of a query language suitable to an ordinary end user. Typically in existing proposals for deductive object-oriented databases the user has to master well both logic-based rule formulation and object-oriented programming. In this paper we introduce a set of high-level querying primitives which increases the degree of declarativeness compared to the deductive object-oriented query languages proposed so far. In terms of these primitives it is possible to offer for end users such application-specific concepts and structures whose interpretation is obvious to users but whose specification is too demanding for them. By combining these primitives in queries the user can integrate data-oriented, behavioral and deductive aspects with each other in a concept-oriented way. Our query language approach is based on the incorporation of deductive aspects to object-orientation. Among others this means that deductive aspects of objects are inherited in the specialization/generalization hierarchy like any other properties of objects.

Design and Implementation of the ROL Deductive Object-Oriented Database System

ROL is a deductive object-oriented database system that has been implemented at the University of Regina. It provides a uniform rule-based declarative language for defining, manipulating and queryi...

Active rule analysis and optimisation in the rock & roll deductive object-oriented database

Active database systems provide facilities that monitor and respond to changes of relevance to the database. Active behaviour is normally described using Event Condition Action rules (ECA-rules), and a number of systems have been developed, based upon different data models, that support such rules. However, experience using active databases shows that while such systems are powerful and potentially useful in many applications, they are hard to program and liable to exhibit poor performance at runtime. This document addresses both of these issues by examining both analysis and optimisation of active rules in the context of a powerful active database system. It is shown how rule analysis methods developed for straightforward active rule languages for relational data models can be extended to take account of rich event description languages and more powerful execution models. It is also shown how the results of analyses can be exploited by rule optimisers, and that multiple query optimisation can be applied in a range of circumstances to eliminate duplicated work during rule processing.

Extending a deductive object-oriented database system with spatial data handling facilities

This paper describes the integration of a spatial data-handling component with the ROCK & ROLL deductive object-oriented database system. The extended ROCK & ROLL system provides much more comprehensive and better integrated database programming facilities than other candidate platforms for spatial information systems. The extended system serves developers with an intuitive, expressive, formally defined collection of spatial data types as primitive types whose operations have state-of-the-art computational complexity. The integration of these types with the object-oriented modelling, imperative programming and deductive querying facilities of ROCK & ROLL makes available a comprehensive and integrated suite of complementary mechanisms for the development of spatial information systems. The paper also provides preliminary benchmark results which indicate that kernel-support for spatial data handling does yield performance gains and that the extended ROCK & ROLL system compares well with a specialist geographic information system and two widely known extensible database systems when the latter are extended with spatial data handling facilities.

A reasoning mechanism for deductive object-oriented databases

Based on the approach implementing a deductive object-oriented database system through the underlying relational database, this paper presents an object reasoning language O-Datalog, which is the extension of Datalog in form and can deal with object-oriented data. For any O-Datalog program, an equivalent Datalog program can be built to help evaluate the original program. This paper focuses on the syntax, semantics and evaluation of O-Datalog.

UDOOM: Uncertainty in Deductive Object-Oriented Data Modeling

Object-oriented data model and deductive data model are two different paradigms which are proposed to extend the traditional databases. However, both of them have some shortcomings. There are some studies which combine these two approaches and obtain a more powerful one. On the other hand, uncertainty modeling and manipulation is required in deductive object-oriented databases to handle complex objects with uncertain properties in knowledge intensive database applications, such as Expert Database Systems, Environmental Information Systems. In this study, a data model UDOOM, is proposed for representation and deduction of complex objects along with their uncertain properties. All of the null, range, and fuzzy type of uncertainty are considered. Deduction is used to be able to cope with relationships and to derive new attribute values and classes.

The formalisation of ROCK & ROLL: A deductive object-oriented database system

This paper describes the formalisation of the deductive object-oriented database system ROCK & ROLL. This is a system which integrates the deductive and object-oriented paradigms in a way that is both clean and consistent, and that has a sound theoretical foundation. The system uses a formally defined object-oriented data model as a foundation for both a logic query language and an imperative data manipulation language in such a way that impedance mismatches are minimised. This paper introduces the facilities offered by ROCK & ROLL, and indicates how their formalisation has been achieved.

ROL: A deductive object base language

This paper presents a novel deductive object-oriented database language, called ROL (Rule-based Object Language), which is being developed at the University of Regina. ROL effectively integrates important features of object-oriented databases and deductive databases into a uniform framework. It supports object identity, complex objects, classes, class hierarchy, multiple inheritance with overriding, and schema. It also supports structured values such as functor objects and sets, treats them as first class citizens, and provides powerful mechanisms for representing both partial and complete information on sets. It is an extension of pure valued-oriented deductive languages such as Datalog and LDL (without grouping) and subsumes them as special cases. Another novelty is the introduction of a new ordering which can capture the intended semantics of nested sets. The ROL language is given a logical semantics based on this new ordering that accounts in a clean and declarative fashion for all of its object-oriented and value-oriented features as well as the usage of schema in a deductive framework.

A deductive object-oriented database system for situated inference in law

Deductive object-oriented databases and situation theory are two important areas of research in the fields of databases and of linguistics. "AI and law" is a new field attracting both AI researchers and legal practitioners. Our research brings together the former two fields with the aim of designing knowledge applications in the latter. This is achieved through a formal model for legal reasoning, /spl Sscr//spl Mscr/ ("Situation-theoretic Model"), and a deductive object-oriented database system, /spl Qscr//spl Uscr//spl Iscr//spl Xscr//spl Oscr//spl Tscr//spl Escr/. The purpose of this paper is to introduce the key features of this formal model, based on situation theory, and to describe how this database system can implement this abstract model for complex legal reasoning applications. Concrete examples from legal precedents are used to illustrate these advanced features.

Design and implementation of ROCK & ROLL: A deductive object-oriented database system

This paper presents an approach to the development of a deductive object-oriented database system, describing the key design decisions and their consequences for implementation. The approach is novel, in that it integrates an object-oriented database system manipulated using an imperative programming language (ROCK) with a logic language for expressing queries and methods (ROLL). The integration is made seamless by deriving both the imperative and logic languages from a single formally defined data model, thereby avoiding impedance mismatches when they are integrated.

Foreword: Deductive object-oriented databases

Foreword: Deductive object-oriented databases

Approaches to deductive object-oriented databases

The paper is concerned with the problem of combining deductive and object-oriented features to produce a deductive object-oriented database system which is comparable to those currently available under the relational view of data modelling not only in its functionality but also in the techniques employed in its construction and use. Under this assumption, the kinds of issues that have to be tackled for a similar research strategy to produce comparable results are highlighted. The authors motivate their terms of comparison, characterize three broad approaches to deductive object-oriented databases and introduce the notion of language convergence to help in the characterization of some shortcomings that have been perceived in them. Three proposals that have come to light in the past three years are looked into in some detail, in so far as they exemplify some of the positions in the space of choices defined. The main contribution of the paper is towards a characterization of the language convergence property of deductive database languages which has a key role in addressing critiques of the deductive and object-oriented database research enterprise. A basic familiarity with notions from deductive databases and from object-oriented databases is assumed.

Deductive Object-Oriented Databases.

Deductive Object-Oriented Databases.

Towards a deductive object-oriented database language

A language for databases with sets, tuples, lists, object identity and structural inheritance is proposed. The core language is logic-based with a fixpoint semantics. Methods with overloading and methods evaluated externally providing extensibility of the language are considered. Other important issues such as updates and the introduction of explicit control are discussed.