Multidatabase update issues (original) (raw)
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Updating Duplicate Values in Distributed Multidatabase Systems
Itedundaiit data for fast ietrieval increase costs of updates in distributed multidatabase systems. 111 tliis paper, costs of updates aie reduced by iutiodiicirig further redundancies. Duplicate values - redundant data that are obtained from relationships of original values - must be updated to preserve their currency when original values a l e updated. 'I'o update duplicate values, relatioiisliips of oiigiual tlat a a i e retrieved in order to cleternline wliicli duplicate values must be updated. If a file with duplicate values satisfies tlie super- key condition introduced in tliis paper, we can perform the retrieval required for updates faster. Redundant data ale added to a database site to satisfy tlie condition.
Correctness and enforcement of multidatabase interdependencies
1993
Many industrial computing environments consist of multiple data processing systems developed along functional or organizational divisions. Each such system usually automates a part of company operations and consists of an application and a centralized DBMS. While the systems are frequently interconnected, they typically are not integrated and provide a limited support for interoperability. An important problem in such environments is to maintain a desired level of consistency of data across these systems, in the presence of concurrent update operations.
2017
Semantic and object-oriented data models provide convenient constructs for the specification of objects, relationships, and operations. The vehicle of representation is a collection of abstractions which parallel the means by which humans prefer to organize complex enterprises. These constructs inherently permit focus on one object, relationship, or operation at a time. Propagation, as a semantic construct, provides the extension of existing modeling capabilities by providing a mechanism for the specification of the update semantics between database objects. Through the analysis of constraints and the propagated actions necessary to maintain them, we attempt to do the following: 1) incorporate additional semantics into the database schema in the form of database propagation rules, 2) in the context of constraints and propagation rules, provide a model independent paradigm for determining if schemata are correct, and 3) provide a vehicle fur the explicit specification of update actio...
INTRODUCTION AND AN OVERVIEW OF DATABASE MANAGEMENT SYSTEMS
Database management systems are standard tools that enable the storage and retrieval of data within modern information systems. Units introducing database concepts are now an accepted part of most computer science courses. These introductory units tend to concentrate on the use of relational database systems. This advanced module, in contrast, deals with implementation aspects of relational systems as well as to the internal structure and performance issues related to DBMS and tests the candidates‟ knowledge of the current enhancements to relational database systems, object oriented database,datamining, data warehousing etc.. This course examines information about database system architecture, the system catalog, query processing and optimization, transaction processing concepts, concurrency control techniques, database recovery techniques, database security and authorization, object-Oriented and object-relational databases, distributed databases and client server architecture, Data Warehousing and Data Mining, and emerging technologies and applications
Updating legacy databases through wrappers: Data consistency management
2004
Abstract Wrapping databases allows them to be reused in earlier unforeseen contexts, such as Web-based applications or federated systems. Data wrappers, and more specifically updating wrappers (that not only access legacy data but also update them), can provide external clients of an existing (legacy) database with a neutral interface and augmented capabilities.