scholarly journals Integrity Constraint Checking in Distributed Nested Transactions over a Database Cluster

2006 ◽  
Vol 9 (2) ◽  
Author(s):  
Stephane Gançarski ◽  
Claudia León ◽  
Hubert Naacke ◽  
Marta Rukoz ◽  
Pablo Santini

This paper presents a solution to check referential integrity constraints and conjunctive global constraints in a relational multi database system. It also presents the experimental results obtained by implementing this solution over a PC cluster with Oracle9i DBMS. The goal of those experimentations is to measure the time spent to check global constraints in a distributed systems. The results show that the overhead induced by our distributed constraint checking is reduced by 50% compared to a centralized checking of constraints.

Author(s):  
Praveen Madiraju ◽  
Rajshekhar Sunderraman ◽  
Shamkant B. Navathe ◽  
Haibin Wang

Global semantic integrity constraints ensure the integrity and consistency of data spanning distributed databases. In this chapter, we discuss a novel representation technique for expressing semantic integrity constraints for XML databases. We also provide the details of XConstraint Checker, a general framework for checking global semantic constraints for XML databases. The framework is augmented with an efficient algorithm for checking these global XML constraints. The algorithm is efficient for three reasons: 1) the algorithm does not require the update statement to be executed before the constraint check is carried out; hence, we avoid any potential problems associated with rollbacks, 2) sub constraint checks are executed in parallel, and 3) most of the processing of algorithm could happen at compile time; hence, we save time spent at run-time. As a proof of concept, we present a prototype of the system implementing the ideas discussed in this paper.


2009 ◽  
pp. 550-569
Author(s):  
Praveen Madiraju ◽  
Rajshekhar Sunderraman ◽  
Shamkant B. Navathe ◽  
Haibin Wang

Global semantic integrity constraints ensure integrity and consistency of data spanning multiple databases. In this paper, we take initial steps towards representing global semantic integrity constraints for XML databases. We also provide a general framework for checking global semantic integrity constraints for XML databases. Furthermore, we set forth an efficient algorithm for checking global semantic integrity constraints across multiple XML databases. Our algorithm is efficient for three reasons: (1) the algorithm does not require the update statement to be executed before the constraint check is carried out; hence, we avoid any potential problems associated with rollbacks, (2) sub constraint checks are executed in parallel, and (3) most of the processing of algorithm could happen at compile time; hence, we save time spent at run-time. As a proof of concept, we present a prototype of the system implementing the ideas discussed in this paper.


10.14311/286 ◽  
2001 ◽  
Vol 41 (6) ◽  
Author(s):  
M. Badawy ◽  
K. Richta

Supporting integrity constraints is essential for database systems. Integrity constraints are used to ensure that the data in a database complies with rules that have been set to establish accurate and acceptable information for a database. Triggers provide a very powerful and flexible means to realize effective constraint enforcing mechanisms. Implementing triggers based on constraint specifications follows some simple rules that are basically independent of a particular commercial database system. This paper gives these rules, which can be used to derive triggers from constraint specifications. A comparison of advantages of constraints and triggers is also given in this paper.


Author(s):  
Hamidah Ibrahim

A vital problem that should be tackled in today’s database system is guaranteeing database consistency. Many techniques and tools have been devised to fulfill this requirement in many interrelated research areas such as concurrency control, security control, reliability control, and integrity control (Eswaran & Chamberlin, 1975; Grefen, 1993). Concurrency control deals with the prevention of inconsistencies caused by concurrent access by multiple users or applications to a database. Security control deals with preventing users from accessing and modifying data in a database in unauthorized ways. Reliability control deals with the prevention of errors due to the malfunctioning of system hardware or software. Integrity control deals with the prevention of semantic errors made by users due to their carelessness or lack of knowledge. This chapter is concerned only with integrity control.


2018 ◽  
Vol 15 (3) ◽  
pp. 821-843
Author(s):  
Jovana Vidakovic ◽  
Sonja Ristic ◽  
Slavica Kordic ◽  
Ivan Lukovic

A database management system (DBMS) is based on a data model whose concepts are used to express a database schema. Each data model has a specific set of integrity constraint types. There are integrity constraint types, such as key constraint, unique constraint and foreign key constraint that are supported by most DBMSs. Other, more complex constraint types are difficult to express and enforce and are mostly completely disregarded by actual DBMSs. The users have to manage those using custom procedures or triggers. eXtended Markup Language (XML) has become the universal format for representing and exchanging data. Very often XML data are generated from relational databases and exported to a target application or another database. In this context, integrity constraints play the essential role in preserving the original semantics of data. Integrity constraints have been extensively studied in the relational data model. Mechanisms provided by XML schema languages rely on a simple form of constraints that is sufficient neither for expressing semantic constraints commonly found in databases nor for expressing more complex constraints induced by the business rules of the system under study. In this paper we present a classification of constraint types in relational data model, discuss possible declarative mechanisms for their specification and enforcement in the XML data model, and illustrate our approach to the definition and enforcement of complex constraint types in the XML data model on the example of extended tuple constraint type.


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