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Abstract. When updating a knowledge base, several problems may arise. One of the most important problems is that of integrity constraints satisfaction. The classic approach to this problem has been to develop methods for checking whether a given update violates an integrity constraint. An alternative approach consists of trying to repair integrity constraints violations by performing additional updates that maintain knowledge base consistency. Another major problem in knowledge base updating is that of view updating; which determines how an update request should be translated into an update of the underlying base facts. We propose a new method for updating knowledge bases while maintaining their consistency. Our method can be used for both integrity constraints maintenance and view updating. It can also be combined with any integrity checking method for view updating and integrity checking. The kind of updates handled by our method are: updates of base facts, view updates, updates of deductive rules, and updates of integrity constraints. Our method is based on events and transition rules, which explicitly define the insertions and deletions induced by a knowledge base update. Using these rules, an extension of the SLDNF procedure allows us to obtain all possible minimal ways of updating a knowledge base without violating any integrity constraint. Key Words. View updating, integrity checking, integrity maintenance. 1.

. In the recent literature the issue of program change via updating rules (also known as revision rules) has been reduced to the issue of obtaining a new set of models, by means of the update rules, from each of the models of an initial program. Any program whose models are exactly the new set of models will count as an update of the original program. Following the classical approaches to theory updating, it is of course essential to start by specifying precisely how a program's models are to change, before even attempting to specify program change. But to stop there is to go only halfway. Another limitation of existing approaches to logic program updating concerns their not dealing with 3-valuedness, i.e. with partial models. The limitation is twofold: on the one hand, only programs under 2-valued semantics are approachable; on the other, when there are contradictory update rules, in lieu of leaving undefined the effects of the contradictory rules and keeping those of the others, no u...

We propose a new method for view updating in deductive databases. The method is based on events and transition rules, which explicitly define the insertions and deletions induced by a database update. Using these rules, an extension of the SLDNF procedure allows us to obtain all valid translations of view update requests. The main advantages of the method are its simplicity, the uniform treatment of insert and delete requests and the integration of integrity checking during the derivation process. The method has the full power of the methods developed so far, without some of their limitations. 1. Introduction The view update problem of relational and deductive databases has attracted a lot of research during the past years [1,2,5,6,7,8,9,11,13,16]. The aim is to provide effective methods for translating view updates into (correct) database updates. Two basic approaches have been proposed to solve the problem. The first suggests treating views as abstract data types, so that the defin...

The integration of object-oriented concepts into deductive databases has been investigated for a certain time now. Various approaches to incorporate updates into deduction have been proposed. The current paper presents an approach which is based on object versioning; different versions of one object may be created and referenced during an update-process. By means of such versions it becomes possible to exert explicit control on the update process during bottom-up evaluation in a rather intuitive way. The units for updates are the result sets of base methods, i.e. methods, whose results are stored in the object-base and are not defined by rules. However, the update itself may be de ned by rules. Update-programs have fixpoint semantics; the fixpoint can be computed by a bottomup evaluation according to a certain stratification.

In this paper, we show how techniques from disjunctive logic programming and classical first-order theorem proving can be used for efficient (deductive) database updates. The key idea is to tranform the given database together with the update request into a disjunctive logic program and apply disjunctive techniques (such as minimal model reasoning) to solve the original update problem. We present two variants of our algorithm both of which are of polynomial space complexity. One variant, which is based on offline preprocessing, is of polynomial time complexity. We also show that both variants are rational in the sense that they satisfy certain rationality postulates stemming from philosophical works on belief dynamics.

In this paper we propose two interpretations of the event rules [Oli91] which provide a common framework for classifying and specifying deductive database updating problems such as view updating, materialized view maintenance, integrity constraints checking, integrity constraints maintenance, repairing inconsistent databases, integrity constraints satisfiability or condition monitoring. Moreover, these interpretations allow us to identify and to specify some problems that have received little attention up to now like enforcing or preventing condition activation. By considering only a unique set of rules for specifying all these problems, we want to show that it is possible to provide general methods able to deal with all these problems as a whole. 1 Introduction Deductive databases generalize relational databases by including not only base facts and integrity constraints, but also deductive rules. Using these rules, derived facts may be derived from facts explicitly stored. Among oth...

The problem considered here is: given a consistent knowledge base and an update, i.e. some first order formula, how can the facts in the knowledge base be changed such that (1) the update becomes true and (2) the constraints remain satisfied. A fact modification satisfying these two requirements is said to be a solution. We will present a technique to compute a solution for a given update and a given knowledge base. The salient features of our approach are: (i) we tackle the problem in a general way and also present a technique for repairing inconsistency, (ii) the user can interact with the system and actively influence the solution to be generated, so we are not forced to generate all possible minimal solutions from which the user finally draws the most preferred one, (iii) solutions are obtained by set-oriented fact processing rather than by single fact accesses to the old knowledge base, and (iv) in contrast to the other techniques proposed so far the consistency of the old knowled...

Abstract: The view update problem is concerned with indirectly modifying those tuples that satisfy a view (or derived table) by an appropriate update against the corresponding base tables. The notion of a deduction tree is defined and the relationship between such trees and the view update problem for indefinite deductive databases is considered. It is shown that a traversal of an appropriate deduction tree yields sufficient information to perform view updates at the propositional level. To obtain a similar result at the first order level, it is necessary (for theoretical and computational reasons) to impose some weak stratification and definiteness constraints on the database. 1 §1 INTRODUCTION. In relational database terminology, a table is referred to as a base table if the database explicitly lists those tuples that hold in the table. By contrast, a table is a view if those tuples that hold in the view are derived by means of some defining formulae, that define the view in terms of base tables (and possibly previously defined views). In deductive

this paper, configuration management is presented from a logic perspective. It is shown that much functionality can be generated automatically when configurations are considered as views on a deductive database and recent results on deductive integrity checking, query optimization, and intensional updates are applied. 1 The Problem Version and configuration management has been a major focus of research in practically all areas of computer-aided design, especially those like software engineering in which the whole design and production process happens within the system. Most research has been invested in the efficient production and reproduction of software components, e.g., in order to avoid excessive re-compilation efforts when only a small portion of a large system has changed. Complementary to this aspect is the consistent (re-)construction of a configuration, i.e., a construction process that satisfies a large set of different kinds o