A Review of integrity constraint maintenance and view updating techniques

Two interrelated problems may arise when updating a database. On one hand, when an update is applied to the database, integrity constraints may become violated. In such case, the integrity constraint maintenance approach tries to obtain additional updates to keep integrity constraints satisfied. On the other hand, when updates of derived or view facts are requested, a view updating mechanism must be applied to translate the update request into correct updates of the underlying base facts. This survey reviews the research performed on integrity constraint maintenance and view updating. It is proposed a general framework to classify and to compare methods that tackle integrity constraint maintenance and/or view updating. Then, we analyze some of these methods in more detail to identify their actual contribution and the main limitations they may present.Postprint (published version

Towards Intelligent Databases

This article is a presentation of the objectives and techniques of deductive databases. The deductive approach to databases aims at extending with intensional definitions other database paradigms that describe applications extensionaUy. We first show how constructive specifications can be expressed with deduction rules, and how normative conditions can be defined using integrity constraints. We outline the principles of bottom-up and top-down query answering procedures and present the techniques used for integrity checking. We then argue that it is often desirable to manage with a database system not only database applications, but also specifications of system components. We present such meta-level specifications and discuss their advantages over conventional approaches

Knowledge Representation Concepts for Automated SLA Management

Outsourcing of complex IT infrastructure to IT service providers has increased substantially during the past years. IT service providers must be able to fulfil their service-quality commitments based upon predefined Service Level Agreements (SLAs) with the service customer. They need to manage, execute and maintain thousands of SLAs for different customers and different types of services, which needs new levels of flexibility and automation not available with the current technology. The complexity of contractual logic in SLAs requires new forms of knowledge representation to automatically draw inferences and execute contractual agreements. A logic-based approach provides several advantages including automated rule chaining allowing for compact knowledge representation as well as flexibility to adapt to rapidly changing business requirements. We suggest adequate logical formalisms for representation and enforcement of SLA rules and describe a proof-of-concept implementation. The article describes selected formalisms of the ContractLog KR and their adequacy for automated SLA management and presents results of experiments to demonstrate flexibility and scalability of the approach.Comment: Paschke, A. and Bichler, M.: Knowledge Representation Concepts for Automated SLA Management, Int. Journal of Decision Support Systems (DSS), submitted 19th March 200

Schema architecture and their relationships to transaction processing in distributed database systems

We discuss the different types of schema architectures which could be supported by distributed database systems, making a clear distinction between logical, physical, and federated distribution. We elaborate on the additional mapping information required in architecture based on logical distribution in order to support retrieval as well as update operations. We illustrate the problems in schema integration and data integration in multidatabase systems and discuss their impact on query processing. Finally, we discuss different issues relevant to the cooperation (or noncooperation) of local database systems in a heterogeneous multidatabase system and their relationship to the schema architecture and transaction processing

Development of an Assertion Model of Integrity Constraints in Object-Oriented Databases

Object-Oriented Databases (OODBs) have been designed to support large and complex programming projects. The data accuracy, consistency, and integrity in OODBs are extremely important for developers and users. Checking the integrity constraints in OODBs is a fundamental problem in database design. Existing OODB Management Systems (OODBMSs) lack to a capability of an ad-hoc declarative specification of enforcing and maintaining integrity constraints that are appeared among attributes in association, composition, and inheritance hierarchies' relationships. A critical problem in the existing OODBs is that they cannot support User-Defmed Constraints (UDCs) that can be defmed in classes with composition (logical or physical composition) and inherence (single or mUltiple inheritance) hierarchies. Integrity constraints in the current OODBMSs are maintained either by disallowing and rolling back transaction or modifying operations that may produce a violation. The constraints must be maintained in the backward direction along the class composition hierarchy as well as in the forward direction. In this work an Assertion Model of Integrity Constraints (AMIC) is proposed. The AMIC keeps the derivation path along with the attributes' relationships that are derived from association, composition, and inheritance hierarchies. The AMIC techniques are designed to implement the needed functions that are collecting the attributes' relationships and checking the integrity constraints. Moreover, AMIC keeps UDCs with their relationships in both single classes and multilevel classes (intra-class and inter-class). Furthermore, the AMIC can maintain constraints in a single object and a set of distributed objects (intra-object and inter-object). Therefore, this makes the new model extendable and can be integrated with any existing constraints' service. A new technique called Detection Method (DM) isdesigned to check the Object Meta Data (OMD) to detect the constraints violation before it occurs. The AMIC is designed for both Centralized Integrity Maintenance (CIM) and Application-Oriented Integrity Maintenance (AOIM). The AMIC can also enforce and maintain structural and logical integrity constraints, in addition to enforce and maintain redundant, inconsistent, and duplicate constraints

Open issues in semantic query optimization in relational DBMS

After two decades of research into Semantic Query Optimization (SQO) there is clear agreement as to the efficacy of SQO. However, although there are some experimental implementations there are still no commercial implementations. We first present a thorough analysis of research into SQO. We identify three problems which inhibit the effective use of SQO in Relational Database Management Systems(RDBMS). We then propose solutions to these problems and describe first steps towards the implementation of an effective semantic query optimizer for relational databases

Policy issues in interconnecting networks

To support the activities of the Federal Research Coordinating Committee (FRICC) in creating an interconnected set of networks to serve the research community, two workshops were held to address the technical support of policy issues that arise when interconnecting such networks. The workshops addressed the required and feasible technologies and architectures that could be used to satisfy the desired policies for interconnection. The results of the workshop are documented