Efficient Detection of XML Integrity Constraints

Název práce: Efektívna detekcia integritných obmedzení v XML Autor: Michal Švirec Katedra: Katedra softwarového inženýrství Vedoucí diplomové práce: RNDr. Irena Mlýnková, Ph.D. Abstrakt: Znalosť integritných obmedzení v XML dátach je jeden z dôležitých aspektov ich spracovania. Avšak aj keď tieto integritné obmedzenia pre dané dáta poznáme, je častým javom, že dané dáta sú voči ním nekonzistentné. Z tohto dôvodu vznikla snaha detekovať tieto nekonzistentosti dát a následne ich opravovať. Táto práca rozširuje a zdokonaľuje doterajšie prístupy opráv XML dokumentov porušujúcich definované integritné obmedzenia, konkrétne takzvané funkčné závislosti. Práca prináša algoritmus začleňujúci váhový model a taktiež zapája užívateľa do procesu hľadania a následného aplikovania vhodnej opravy nekonzistentných XML dokumentov. Súčasťou práce sú experimentálne výsledky. Klíčová slova: XML, funkčná závislosť, porušenie funkčných závislostí, oprava porušeníTitle: Efficient Detection of XML Integrity Constraints Author: Michal Švirec Department: Department of Software Engineering Supervisor: RNDr. Irena Mlýnková, Ph.D. Abstract: Knowledge of integrity constraints covered in XML data is an impor- tant aspect of efficient data processing. However, although integrity constraints are defined for the given data, it is a common phenomenon that data violate the predefined set of constraints. Therefore detection of these inconsistencies and consecutive repair has emerged. This work extends and refines recent approaches to repairing XML documents violating defined set of integrity constraints, specif- ically so-called functional dependencies. The work proposes the repair algorithm incorporating the weight model and also involve a user into the process of de- tection and subsequent application of appropriate repair of inconsistent XML documents. Experimental results are part of the work. Keywords: XML, functional dependency, functional dependencies violations, vi- olations repairDepartment of Software EngineeringKatedra softwarového inženýrstvíFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult

Semi-automatic support for evolving functional dependencies

During the life of a database, systematic and frequent violations of a given constraint may suggest that the represented reality is changing and thus the constraint should evolve with it. In this paper we propose a method and a tool to (i) find the functional dependencies that are violated by the current data, and (ii) support their evolution when it is necessary to update them. The method relies on the use of confidence, as a measure that is associated with each dependency and allows us to understand \u201dhow far\u201d the dependency is from correctly describing the current data; and of goodness, as a measure of balance between the data satisfying the antecedent of the dependency and those satisfying its consequent. Our method compares favorably with literature that approaches the same problem in a different way, and performs effectively and efficiently as shown by our tests on both real and synthetic databases