Cursada 2004
Profesor a Cargo: Lic. Laura C. Rivero lrivero@exa.unicen.edu.ar
Auxiliar: Ing. Viviana C. Ferraggine vferra@exa.unicen.edu.ar
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.
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.
Hainaut, Jean-Luc, “A
Generic Entity-Relationship Model”, RP-89-001. Institut d’Informatique, Notre-Dame de la Paix,
Namur, Belgium. January,
1989.
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.
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
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.
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.
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.
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
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.
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
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.
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”.
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.
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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.
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
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.
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
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