INTEGRIDAD EN BASES DE DATOS

Cursada 2004

 

Profesor a Cargo: Lic. Laura C. Rivero                  lrivero@exa.unicen.edu.ar

                Auxiliar: Ing. Viviana C. Ferraggine          vferra@exa.unicen.edu.ar

Contenidos

Unidad 1: Conceptos de integridad.

Unidad 2: Problemas de diseño de esquema.

Unidad 3: Restricciones Referenciales.

Unidad 4: Restricciones de Integridad Referencial.

Unidad 5: Información Faltante.

Unidad 6: Integridad en bases de datos post-relacionales.

 

Unidad 1: Conceptos de integridad.

Integridad de datos en el mundo real y su representación en el mundo de las bases de datos. Clasificación de las restricciones. Restricciones de dominio, de relaciones y tablas y restricciones generales. Aserciones y triggers.

Bibliografía: 

Artículos

Hainaut, Jean-Luc, “A Generic Entity-Relationship Model”, RP-89-001. Institut d’Informatique, Notre-Dame de la Paix, Namur, Belgium. January, 1989.

http://citeseer.ist.psu.edu/cache/papers/cs/25319/ftp:zSzzSzftp.info.fundp.ac.bezSzpubzSzpublicationszSzRPzSzRP-89-001.pdf/hainaut89generic.pdf

Abstract:

The objective of the paper is to put forward a general framework allowing the specification, comparison and conversion of most information and data models currently proposed for Information System design, be they at the conceptual or at the DBMS levels. That framework is based on an extended relational model that includes the concepts of entity domain and of complex domain. The analysis of the constructs available in current information models, and particularly E-R models, demonstrates the ability of the extended relational model to express these constructs without loss of semantics. The Generic Entity-relationship (GER) model is a large subset of the extended relational model that can uniquely represent the concepts of most current information models, while being more regular, less complex and more powerful than their union. By further augmenting the GER with two simple logical implementation constructs we extend it to the expression of DBMS-dependent models.

 

Wand, Y., Storey, V., Weber, R., “An Ontological Analysis of the Relationship Construct in Conceptual Modeling”, ACM Transactions Database Systems, Vol. 24 Nro. 4, December 1999, Pages 494-528.

http://portal.acm.org/citation.cfm?id=331983.331989

Abstract:

Conceptual models or semantic data models were developed to capture the meaning of an application domain as perceived by someone. Moreover, concepts employed in semantic data models have recently been adopted in object-oriented approaches to systems analysis and design. To employ conceptual modeling constructs effectively, their meanings have to be defined rigorously. Often, however, rigorous definitions of these constructs are missing. This situation occurs especially in the case of the relationship construct. Empirical evidence shows that use of relationships is often problematical as a way of communicating the meaning of an application domain. For example, users of conceptual modeling methodologies are frequently confused about whether to show an association between things via a relationship, an entity, or an attribute. Because conceptual models are intended to capture knowledge about a real-world domain, we take the view that the meaning of modeling constructs should be sought in models of reality. Accordingly, we use ontology, which is the branch of philosophy dealing with models of reality, to analyze the meaning of common conceptual modeling constructs. Our analysis provides a precise definition of several conceptual modeling constructs. Based on our analysis, we derive rules for the use of relationships in entity-relationship conceptual modeling. Moreover, we show how the rules resolve ambiguities that exist in current practice and how they can enrich the capacity of an entity-relationship conceptual model to capture knowledge about an application domain.

 

Soares da Silva, A, Laender, A.H.F., Casanova, M.A. “On the Correct Relational Representation of Complex Specialization Structures”. Information Systems Vol 25 Nro. 6-7 pp 399-415.

Versión resumida en:  http://www.inf.puc-rio.br/~casanova/ReferenciasBD/er97.pdf

Abstract:

The mapping of ER schemas containing complex specialization structures into the relational model requires the use of specific strategies to avoid inconsistent states in the final relational database. In this paper, we generalize a strategy for mapping such structures and characterize the class of ER schemas for which it generates relational schemas that correctly captures their semantics. We also show that this strategy may be adapted for generating optimized relational schemas for which the number of inclusion dependencies to be enforced is reduced.

 

Balaban, M., Shoval, P., “Enhancing the ER Model with Integrity Methods”. Journal of Database Management. Vol.10 Nro 4.Octubre-Diciembre 1999. pp11-20.

http://www.cs.bgu.ac.il/~mira/DBM.pdf

Abstract:

Entity Relationship (ER) schemas include cardinality constraints, that restrict the dependencies among entities within a relationship type. The cardinality constraints have direct impact on application transactions, since insertions or deletions of entities or relationships might affect related entities. Application transactions can be strengthened to preserve the consistency of a database with respect to the cardinality constraints in a schema. Yet, once an ER schema is translated into a logical database schema, the direct correlation between the cardinality constraints and application transaction is lost, since the components of the ER schema might be decomposed among those of the logical database schema.

We suggest to extend the Enhanced ER (EER) data model with integrity methods that take the cardinality constraints into account. The integrity methods can be fully defined by the cardinality constraints, using a small number of primitive update methods, and are automatically created for a given EER diagram. A translation of an EER schema into a logical database schema can create integrity routines by translating the primitive update methods alone. These integrity routines may be implemented as database procedures, if a relational DBMS is utilized, or as class methods, if an object oriented DBMS is utilized.

 

Soares da Silva, A, Laender, A.H.F., Casanova, M.A. “On the Relational Representation of Complex Specialization Structures”. Information Systems Vol 25 Nro. 6-7 pp 399-415.

Abstract:

The mapping of entity-relationship schemas (ER schemas) that contain complex specialization structures into the relational model requires the use of specific strategies to avoid inconsistent states in the final relational database. In this paper, we show that for this mapping to be correct it is required to enforce a special kind of integrity constraint, the key pairing constraint (KPC). We present a mapping strategy to use simple inclusion dependencies to enforcement KPC and show that this strategy can be used to correctly map specialization structures that ere more general that the simple specialization structures considered by previous strategies.

 

Dullea, J., Song, I., “An Analysis of Cardinality Constraints in Redundant Relationships”.  ACM International Conference on Information and Knowledge Management. 1997.

http://www.cis.drexel.edu/faculty/song/Papers/CIKM97-ER.pdf

Abstract:

In this paper, we present a complete analysis of redundant relationships in the entity-relationship model. Existing approaches use the concept of functional dependencies for identifying redundancy but ignore minimum cardinality constraints that carry important information about the structure of the model. Research literature on the topic is rare and usually is confined to the ‘Many to One’-‘mandatory participation’ case. Our approach differs from previous works in that we consider both maximum and minimum cardinality constraints to analyze the 4096 cases required to perform a complete study. Our approach first looks at the maximum cardinality constraints to develop a set of general rules to identify groups of trivial and ambiguous structures, and then we give greater consideration to the minimum cardinality constraints in those groups that require detailed investigation. With this approach we have provided a thorough pattern analysis of redundant relationships from both a structural and semantic view. The scope of this paper focuses on a  complete and thorough analysis of a binary relationship redundant with respect to the composite of two binary  elationships and establishes inferences that can extend this analysis to the more complex ‘n-relationship path’ case. We  provide a complete set of heuristics for identifying redundant relationships that can be easily applied by data modelers and system analysis people.

 

Markowitz, V.M. and Makowsky, J.A., “Identifying Extended Entity-Relationship Object Structures in Relational Schemas”, IEEE Transactions on Software Engineering. Vol 16, No. 8, 777-790, Agosto 1990.

 http://ieeexplore.ieee.org/xpl/abs_free.jsp?arNumber=57618

Abstract:

Relational schemas consisting of relation-schemes, key dependencies and key-based inclusion dependencies (referential integrity constraints) are considered. Schemas of this form are said to be entity-relationship (EER)-convertible if they can be associated with an EER schema. A procedure that determines whether a relational schema is EER-convertible is developed. A normal form is proposed for relational schemas representing EER object structures. For EER-convertible relational schemas, the corresponding normalization procedure is presented. The procedures can be used for analyzing the semantics of existing relational databases and for converting relational database schemas into object-oriented database schemas.

 

Markowitz, V.M. and Shoshani, A., “Representing Extended Entity-Relationship Structures in Relational Databases: A Modular Approach”, ACM Transactions on Database Systems. Vol. 17 No. 3, 423-464, Septiembre 1992.

http://portal.acm.org/citation.cfm?id=132273&jmp=indexterms&coll=GUIDE&dl=ACM

Abstract:

A common approach to database design is to describe the structures and constraints of the database application in terms of a semantic data model, and then represent the resulting schema using the data model of a commercial database management system. Often, in practice, Extended Entity-Relationship (EER) schemas are translated into equivalent relational schemas. This translation involves different aspects: representing the EER schema using relational constructs, assigning names to relational attributes, normalization, and merging relations. Considering these aspects together, as is usually done in the design methodologies proposed in the literature, is confusing and leads to inaccurate results. We propose to treat separately these aspects and split the translation into four stages (modules) corresponding to the four aspects mentioned above. We define criteria for both evaluating the correctness of and characterizing the relationship between alternative relational representations of EER schemas.

Libros

Cuadra, D., Nieto, C., Martinez, P., Castro, E., Velasco, M., “Preserving Relationship Cardinality Constraints in Relational Schemata”, Chapter III, en Database Integrity: Challenges & Solutions. Doorn J.H., Rivero, L.C. (Eds.). Idea Group Publishing. 2002. pp.66-112.

 

De Cood, Codd, E. (1990) The relational model for database management. Version 2. Addison Wesley Publ. Co.

 

Volver a Contenidos

 


Unidad 2: Problemas de diseño de esquema.

Problemas de diseño de esquemas relacionales: fan trap, cham trap y otros.  Modelado de entidades vs. Atributos. Relaciones ternarias y de mayor orden. Su conversión a esquemas relacional y los problemas de integridad vinculados.

Bibliografía:

Artículos

Dey, D., Storey, V.C., Barron, T.M. “Improving Database Design through the Analysis of Relationships”. ACM Transactions on Database Systems. Vol 24 Nro. 4 December 1999. pp. 453-486. http://portal.acm.org/citation.cfm?id=331984

Abstract:

Much of the work on conceptual modeling involves the use of an entity-relationship model in which binary relationships appear as associations between two entities. Relationships involving more than two entities are considered rare and, therefore, have not received adequate attention. This research provides a general framework for the analysis of relationships in which binary relationships simply become a special case. The framework helps a designer to identify ternary and other higher-degree relationships that are commonly represented, often inappropriately, as either entities or binary relationships. Generalized rules are also provided for representing higher-degree relationships in the relational model. This uniform treatment of relationships should significantly ease the burden on a designer by enabling him or her to extract more information from a real-world situation and represent it properly in a conceptual design

 

Jones, T.H., Song, Il-Yeol, “Analysis of Binary/Ternary Cardinality Combinations in Entity-Relationship Modeling”. Data & Knowledge Engineering. Vol 19 No 1. 1996, pp. 39-64.  http://www.cis.drexel.edu/faculty/song/Papers/Dke96.pdf

Abstract:

In this paper, we discuss the simultaneous existence, and relationships, between binary and ternary relationships in entity-relationship (ER) modeling. We define the various interpretations that can be applied to the simultaneous existence of ternary and binary relationships having the same participating entities. We have identified that only certain cardinalities are permitted to exist simultaneously in such ER structures. We demonstrate which binary relationship cardinalities are permitted within ternary relationships, during ER modeling. We develop an Implicit Binary Cardinality (IBC) rule, which states that, in any ternary relationship, the cardinality of any binary relationship embedded in the ternary, is many-to-many when there are no explicit constraints on the data instances. We then present an Explicit Binary Permission (EBP) rule, which explains and enumerates all permitted binary relationships for various cardinalities of ternary relationships. Finally we present an Implicit Binary Override (IBO) rule, which states that the implicit binary cardinalities can be constrained in a ternary relationship by an explicitly imposed binary relationship. We then use these rules to consider the further implicit dynamics of ternary relationships when multiple binary relationships are imposed.

In discussing these findings, we consider the rules in the context of supporting functional dependency analysis. The relevance of the findings is presented in the context of ensuring that all functional dependencies associated with ternary relationships are correctly applied and identifying the potential for decomposing the ternary relationship into multiple binary relationships based on all explicit functional dependencies.

 

Camps Paré, C. “From Ternary Relationship to Relational Tables : A case Against Common Beliefs”. ACM SIGMOD Record. Vol. 31,  Issue 2  (June 2002). pp. 46 – 49.

http://portal.acm.org/citation.cfm?id=565125

Abstract:

The transformation from n-ary relationships to a relational database schema has never been really fully analyzed. This paper presents one of the several ternary cases ignored by the ER-to-RM literature. The case shows that the following common belief is wrong: Given a set of FDs over a table resulting in a non-3NF situation, it is always possible to obtain a fully equivalent set of 3NF tables, without adding other restrictions than candidate keys and elementary inclusion dependencies.

 

McAllister, A. “Complete rules for n-ary relationship cardinality constraints”. Data & Knowledge Engineering. Vol. 27, Nro. 3, Octubre 1998. pp. 255-288. Elsevier.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TYX-3V45H52-1&_coverDate=10%2F01%2F1998&_alid=204559700&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5630&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=0f916efc4fe71075c379f2d16b25146b

Abstract:

An extended approach is presented for modeling data relationships that involve multiple entities. This approach unifies the relationship cardinality constraints defined by a variety of existing approaches into a common framework and extends the types of constraints captured. A concise tabular notation for specifying such constraints is introduced. The result is a modeling technique that captures more completely the nature of data relationships. Rules are defined for identifying inconsistencies among cardinality constraints specified for a given data relationship. Specific subsets of these rules are shown to be complete for four of the most commonly used variations of cardinality constraints. These rules extend work done in axiomatization of functional and numerical dependencies for relational databases into the area of conceptual data models.

 

Dullea, J. Song, I., “An Analysis of Structural Validity of Ternary Relationships in Entity Relationship Modeling”, Data & Knowledge Engineering 47 (2003) 167–205.

http://www.cis.drexel.edu/faculty/song/Papers/DKE_03_Validity.pdf

Abstract:

We explore the criteria that contribute to the structural validity of modeling structures within the entityrelationship (ER) diagram. Our approach examines cardinality constraints in conjunction with the degree of the relationship to address constraint consistency, state compliance, and role uniqueness issues to derive a complete and comprehensive set of decision rules. Unlike typical other analyses that use only maximum cardinality constraints, we have used both maximum and minimum cardinality constraints in de.ning the properties and their structural validity criteria yielding a complete analysis of the structural validity of recursive, binary, and ternary relationship types. Our study evaluates these relationships as part of the overall diagram and our rules address these relationships as they coexist in a path structure within the model. The contribution of this paper is to provide a comprehensive set of decision rules to determine the structural validity of any ERD containing recursive, binary, and ternary relationships. These decisión rules can be readily applied to real world data models regardless of their complexity. The rules can easily be incorporated into the database modeling and designing process, or extended into case tool implementations.

 

Jones, T.R., Song, I., “Binary Equivalents of Ternary Relationships in Entity-Relationship Modeling: a Logical Decomposition Approach”, Journal of Database Management, April-June, 2000, pp. 12 –19.

http://www.cis.drexel.edu/faculty/song/Papers/Jdb99.pdf

Abstract:

Little work has been completed which addresses the logical composition and use of ternary relationships in entity-relationship modeling. Many modeling notations and most CASE tools do not allow for ternary relationships. Alternative methods and substitutes for ternary relationship structures do not necessarily reflect the original logic, semantics or constraints of a given situation. Furthermore, it has been shown that ternary relationships can be constrained by additional implicit binary constraints which do not occur in the logic of binary relationships.

This paper develops an analytical perspective of ternary relationships. We investigate the logical relationships implicit to the ternary structure and then identify potential simplification through decomposition into binary equivalents. These alternative binary equivalents allow retention of the implicit logical structure, and consequently also retain the semantics of the original structure. The analysis investigates equivalency of lossless decompositions, preservation of functional dependencies and finally the ability to preserve update constraints (insertions and deletions). We identify which ternary relationships have true, fully equivalent, binary equivalents and those which do not. We provide an exhaustive analysis of cardinality combinations found in ternary relationships which practitioners can use to guide the way in which they deal with ternary relationships in conceptual modeling.

 

Camps, R., “Transforming N-ary Relationships to Database Schemas: An Old and Forgotten Problem”

http://www.lsi.upc.es/dept/techreps/listado_concreto.php?id=396

Abstract:

The n-ary relationships, have been traditionally a source of confusion and still are. One important source of confusion is that the term "cardinality" in a relationship has several interpretations, two of them being very popular. But none of the two approaches, nor the two together, allow us to express all the possible cardinality patterns. The transformations from all the possible patterns to database schemas have never been fully discussed by the existing textbooks and papers that deal with database design. Using the fourteen ternary patterns as example, we discuss these transformations particularly the transformations from the patterns ignored in the literature.

 

Badía, A., “Entity-Relationship Modeling Revisited”, ACM SIGMOD Record
Vol. 33 ,  Issue 1  (Marzo 2004) pp. 77 - 82.

 http://www.acm.org/sigmod/record/issues/0403/B5.AntonioBadia.pdf

Abstract:

In this position paper, we argue the modern applications require databases to capture and enforce more domain semantics than traditional applications. We also argue that the best way to incorporate additional semantics into database systems is by capturing the added information in conceptual models and then using it for database design. In this light, we revisit Entity-Relationship models and investigate ways in which such models could be extended to play a role in the process. Inspired by a paper by Rafael Camps Pare ([2]), we suggest avenues of research in the issue.

Libros

Cuadra, D., Nieto, C., Martinez, P., Castro, E., Velasco, M., “Preserving Relationship Cardinality Constraints in Relational Schemata”, Database Integrity: Challenges & Solutions. Idea Group Publishing. 2002. pp.66-112.

 

Volver a Contenidos


Unidad 3: Restricciones Referenciales.

Restricciones Referenciales. Diseños anómalos. Dependencias de inclusión no basadas en clave. Manipulaciones conflictivas por la presencia de objetos ocultos. Elicitación y conversión de objetos ocultos y restricciones en un esquema relacional.

 

Bibliografía:

Artículos

Casanova, M.A., Tucherman, L., Furtado, A.L. Braga, A.P., “Optimization of Relational Schemas Containing Inclusión Dependencias”.  Proceedings of the Fifteenth Internacional Conference on Very Large Data Bases Amsterdam, 1989. pp 317-325

http://www.vldb.org/conf/1989/P317.PDF

Abstract:

A two-step optimization strategy for relational schemas that contains a class of inclusion dependencies is described. Both steps take into account additional information that indicates how to preserve each inclusion dependency in the presence of insertions and deletion. The first step eliminates inclusion dependencies, which are redundant with respect to both the semantics of the data and the behavior of the transactions. The second step discards dependencies through a structural transformation that again preserves the semantics of the data and of the transactions and that applies both to ihrF and to iV# relational schemas.

 

Soares da Silva, A., Laender, A.H.F., Casanova, M.A., “An Approach to Maintaining Optimized Relational Representations of Entity-Relationship Schemas”. In Thalheim, B. (Eds.). Proceedings Conceptual Modeling - ER'96, 15th International Conference on Conceptual Modeling, Cottbus, Germany, October, 1996. Springer-Verlag. pp. 292-308.

http://www.sigmod.org/sigmod/dblp/db/conf/er/SilvaLC96.html

Abstract:

 

Soares da Silva, A., Laender, A.H.F., Casanova, M.A., “On the Correct Relational Representation of Complex Specialization Structures”.

http://www.inf.puc-rio.br/~casanova/ReferenciasBD/er97.pdf

Abstract:

The mapping of ER schemas containing complex specialization structures into the relational model requires the use of specific strategies to avoid inconsistent states in the final relational database. In this paper, we generalize a strategy for mapping such structures and characterize the class of ER schemas for which it generates relational schemas that correctly captures their semantics. We also show that this strategy may be adapted for generating optimized relational schemas for which the number of inclusion dependencies to be enforced is reduced.

 

Casanova, M.A., Tucherman, L., Furtado, A.L., “Enforcing Inclusion Dependencies and Referential Integrity”. In Proc. of Fourteenth VLDB, pages 38{49, August 1988.

http://www.vldb.org/conf/1988/P038.PDF

Abstract:

The general architecture of a monitor that enforces inclusion dependencies and referential integrity is described. The monitor traces the operations a user submits in a session and can either modify an operation or propagate it, depending on additional information the database designer provided at design time. Propagation is implemented by executing new operations when the session terminates, using summary data collected during normal processing.

 

Kolp, M., Zimanyi, E., “Enhanced ER to relational mapping and interrelational normalization”. Information and Software Technology 42 (2000) 1057±1073. Elsevier.

http://yeroos.isys.ucl.ac.be/file.pdf/P-00-02.pdf

Abstract:

This paper develops a method that maps an enhanced Entity-Relationship (ER1) schema into a relational schema and normalizes the latter into an inclusion normal form (IN-NF). Unlike classical normalization that concerns individual relations only, IN-NF takes interrelational redundancies into account and characterizes a relational database schema as a whole. The paper formalizes the sources of such interrelational redundancies in ER1 schemas and specifies the method to detect them. Also, we describe briefly a Prolog implementation of the method, developed in the context of a Computed-Aided Software Engineering shell and present a case study.

 

Rivero, L.C., Ferraggine, V.E., Doorn, J.H., “Reingeniería de Bases de Datos: Un Enfoque Basado en el Análisis de Dependencias de Inclusión”. Revista Colombiana de Computación. Vol. 4, N° 2 December 2003.

http://www.unab.edu.co/editorialunab/revistas/rcc/pdfs/r42_art5_c.pdf

Abstract:

La conversión de un esquema de bases de datos en otro con mayor contenido semántica es un tema de investigación actual, y un tópico con aplicación en varias áreas de desarrollo tales como integración de esquemas, migración de sistemas “legacy” y reingeniería de modelos de datos desactualizados o de pobre calidad. Las dependencias de inclusión constituyen uno de los conceptos clave para llevar a cabo la reingeniería de esquemas de bases de datos. Con frecuencia, formas atípicas de dependencias de inclusión aparecen como consecuencia de un diseño desnormalizado, por la presencia de construcciones complejas tales como relaciones de orden superior con restricciones de integridad adicionales en forma de relaciones de menor orden, o simplemente cuando objetos de la realidad y sus relaciones han sido mal representados en el modelo conceptual. Específicamente, éste es el caso de reglas del negocio plasmadas incorrectamente como dependencias de inclusión atípicas. Este trabajo presenta un estudio exhaustivo de las dependencias de inclusión y un análisis de su posible origen, en el contexto de la reingeniería de esquemas relacionales. Se proponen heurísticas para la conversión de esquemas conteniendo tales dependencias en otros equivalentes con sólo restricciones de integridad referencial. En caso de encontrar dependencias atípicas remanentes, se provee una interpretación de su significado y necesidad de mantenimiento.

 

Volver a Contenidos


Unidad 4: Restricciones de Integridad Referencial.

Restricciones de integridad referencial. Redes de restricciones referenciales. Problemas de redundancia e incoherencia. Coexistencia de clausulas de integridad, triggers, chequeos y aserciones generales. Modelo de ejecución de SQL-3. Conflictos de restricciones de integridad referencial revisados según este modelo.

Bibliografía:

Markowitz, V.M., “Referential Integrity Revisited: An Object-Oriented Perspective”, Proceedings of 16th VLDB Conference, Brisbane, Australia, 578-589, 1990. http://www.vldb.org/conf/1990/P578.PDF

Abstract:

Referential integrity underlies the relational representation of objeceoriented structures. The concept of referential integrity in relational databases is hindered by the confusion surrounding both the concept itself and its implementation by relational database management systems (RDBMS). Most of this confusion is caused by the diversity of relational representations for object-oriented structures. We examine the relationship between these representations and the structure of referential integrity constraints, and show that the controversial structures either do not occur or can be avoided in the relational representations of object-oriented structures.

Referential integrity is not supported uniformly by RDBMS products. Thus, referential integrity constraints can be specified in some RDBMSs non-procedurally (declaratively) , while in other DBMSs they must be specified procedurally. Moreover, some RDBMSs do not allow the specification of certain referential integrity constraints. We discuss the referential integrity capabilities provided by three representative RDBMSs, DB2, SYBASE, and INGRES.

 

Markowitz, V.M., “Problems Underlying the Use of Referential Integrity in Relational Database Management Systems”. Proceedings of 7th Conference on Data Engineering, Japon., 41 -49, 1991.

Abstract:

Referential integrity constraints express in relational databases existence dependencies between tuples. Although it is known that certain referential integrity structures may cause data manipulation problems, the nature of these problems has not been explored and the conditions for avoiding them have not been formally developed. In this paper we examine these data manipulation problems and formally develop safeness conditions for avoiding them. Next, we discuss the problem of specifying safe referential integrity constraints in three representative relational database management systems, IBM's DB2, SYBASE, and INGRES

 

Cochrane, R., Pirahesh, H., Mattos N., “Integrating Triggers and Declarative Constraints in SQL Database Systems”.

http://citeseer.ist.psu.edu/cache/papers/cs/3251/http:zSzzSzwww.informatik.uni-trier.dezSz~leyzSzvldbzSzCochranePM96zSzArticle.pdf/integrating-triggers-and-declarative.pdf

 

Schewe, K-D.,“Well-Behaving Rule Systems for Entity-Relationship and Object-Oriented Models”. Conceptual Modeling - ER '97, 16th International Conference on Conceptual Modeling, Los Angeles, California, USA, November 3-5, 1997.

http://fims-www.massey.ac.nz/~kdschewe/pub/articles/ER97.ps

 

Markowitz, V.M., “Safe Referential Integrity Structures in Relational Database”, Proceedings of 17th VLDB Conference, Barcelona, España, 123-132, Septiembre 1991.

 

Markowitz, V.M., “Safe Referential Integrity and Null Constraint Structures in Relational Databases”, Information Systems. Vol. 19 ,  Issue 4  (June 1994) Pages: 359 - 378 1994.

 

Reinert, J, “Ambiguity for Referential Integrity is Undecidable”, Proceedings of 7th Working Conference on Scientifical Database Management, Charlottesville, VA. IEEE, Computer Society Press, 207-216, Septiembre 1994.

 

Schewe, K-D, “Consistency Enforcement in Entity-Relationship and Object-Oriented Models” Data and Knowledge Engineering, vol. 28 , 121-140, 1998.

 

May, Wolfgang Ludäscher, Bertram “Understanding the Global Semantics of Referential Actions using Logic Rule”, ACM Transactions on Database Systems, , Dic 2002

 

Ludäscher, B., May,  W., Lausen, G., “Referential actions as logical rules”. Symposium on Principles of Database Systems. Proceedings of the sixteenth ACM SIGACT-SIGMOD-SIGART Symposium on Principles of database systems. Tucson, Arizona, United States. pp: 217 – 227.1997.

 

 

Volver a Contenidos

 


Unidad 5: Información Faltante.

Información incompleta en el modelo relacional. Diferentes tipos de nulos. Extensión de la integridad referencial con valores nulos. Actualización de relaciones incompletas. Operaciones relacionales en relaciones con información faltante. Lógica de tres y cuatro valores.

Bibliografía:

Libros:

Date, J.C. Capitulo 18: Información Faltante. “Introducción a los Sistemas de Bases de Datos”, Séptima Edición. Parson Educación. 2001. pp 584-611.

 

Meldenson, A., Ale, J., Introducción a las Bases de Datos Relacionales. Prentice Hall. 2000

 

Volver a Contenidos


Unidad 6: Integridad en bases de datos post-relacionales.

Integridad en bases de datos post-relacionales. Algunos conceptos de integridad en bases de datos objeto-relacional, orientadas a objeto y de información espacio-temporal. Características orientadas a objetos del estándar y restricciones de integridad asociativas.

Bibliografía:

Artículos

 

Schewe, K-D and Thalheim, B., Towards a Theory of Consistency Enforcement, Acta Informatica, vol. 36, 97-141, 1999

 

Schewe, K.-D., Design Theory for Advanced Datamodels Keynote address In M. Orlowska, J. Roddick (Eds.)., Proc. Australasaian Database Conference 2001, , 2001

Libros

 

Stonebraker, M. (1996) Object-relational DBMSs. The next great wave. Morgan Kauffman Publishers.

 

Schiel, U., “Integrity Maintenance In Extensible Database”. Chapter X, en Database Integrity: Challenges & Solutions. Doorn J.H., Rivero, L.C. (Eds.). Idea Group Publishing. 2002. pp. 322-334.

 

Volver a Contenidos