We propose a new method for generating consistency-preserving transaction programs for (view) updates in deductive databases. The method augments the deductive database schema with a set of transition and internal events rules, which explicitly define the database dynamic behaviour in front of a database update. At transaction-design-time, a formal procedure can use these rules to automatically generate parameterised transaction programs for base or view-update transaction requests. This is done in such a way that those transactions will never take the database into an inconsistent state. In this paper we extend a previous version of the method by incorporating existentially defined rules. Within this context, synthesis outputs and processes are provided. The method, implemented in Prolog using meta-programming techniques, draws from our previous work in deductive databases, particularly in view updating and integrity constraints checking. KEYWORDS Deductive databases, Database Softwar...

An important problem that arises when updating a deductive database is the one related to integrity constraints maintenance. That is, given a consistent database and an update request, to obtain all possible ways of updating the base facts such that the request is satisfied while consistency of the database is maintained. This problem becomes more complex when view updates may also be requested since these updates must be translated into base fact updates. In this paper we present a method for providing automatic support in these situations. Our method takes into account information about the keys of the predicates and it is able to handle updates which consist of a set of insertions, deletions and/or modifications of base and derived predicates. Our interest in this paper is to describe the current status of our work towards providing an effective and efficient method for updating consistent deductive databases. 1. Introduction Deductive databases generalize relational databases by in...

We propose a new method for generating consistency-preserving transaction programs for (view) updates in deductive databases. The method augments the deductive database schema with a set of transition and internal events rules, which explicitly define the database dynamic behaviour in front of a database update. At transaction-design-time, a formal procedure can use these rules to automatically generate parameterised transaction programs for base or view-update transaction requests. This is done in such a way that those transactions will never take the database into an inconsistent state. In this report we extend a previous version of the method by incorporating existentially defined rules, and formalising their treatment. Within this context, synthesis outputs and processes are provided. The method, implemented in Prolog using meta-programming techniques, draws from our previous work in deductive databases, particularly in view updating and integrity constraints checking. KEYWORDS Ded...

. A method and a tool for supporting transaction design in conceptual modelling of information systems is presented. The method derives automatically a transaction specification that integrates in a uniform manner the updating of base and derived information and the checking and maintenance of integrity within an information base conceptual schema. Transaction specifications thus obtained achieve their intended purpose and guarantee that information base consistency will be preserved. When there are several possible solutions, the method derives all of them. The designer may then intervene in various ways in order to select the most appropriate ones. From this choice on, the transaction processing system and the enduser can also play a role in the final application of the transaction specification, for this one can be directly executable. Using a declarative, logic-based approach, the method is general, and can be adapted easily to most conceptual modelling methodologies. 1. Introducti...

A dynamic constraint expresses conditions that involve facts of two or more states of the database. Since the database is expected to satisfy such conditions, a fundamental issue about integrity constraints is their enforcement. Many methods have been developed in this respect. The purpose of this paper is to present a brief survey of methods for dynamic constraint definition and enforcement. Also we classify and compare these methods with respect to several relevant features. Keywords Dynamic integrity constraints, integrity enforcement, survey, classification * Permanent address: Diretoria de Processamento de Dados, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil (E-mail: mamelia@pitanga.ufu.br) 1 INTRODUCTION In the field of information systems and databases, the term integrity normally refers to the correctness or validity of the stored data, as defined explicitly by means of integrity rules or integrity constraints (Grefen and Apers, 1993). Integrity is a very impo...

We overview the architecture of a newly-born deductive database management system that is to provide advanced update and rule enforcement capabilities within an integrated and theoretically well-founded framework. The system builds up on previous theoretical results and systems of others-for the semantics, query, storage and transaction management needs- and of our own previous research and prototypes-for the advanced update and rule enforcement purposes. We hope that our approach will help to fill an important gap within current deductive database management systems prototypes and products. KEYWORDS Deductive Databases; Database Updating; View, Integrity and Trigger Rule Enforcement; Data Base Management Systems October - 1 - 1. Introduction The emerging needs for more "intelligence" within information systems and other computerbased applications are posing a high demand on infrastructure technology for their implementation and use. Within this market-pull context, Deductive Datab...