This paper describes the design and functionality of a graphical user interface (GUI) written in Java Swing that is used to support instructional activities associated with teaching object-oriented database (OODB) con...
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ISBN:
(纸本)1581133294
This paper describes the design and functionality of a graphical user interface (GUI) written in Java Swing that is used to support instructional activities associated with teaching object-oriented database (OODB) concepts. The GUI supports the manipulation of objects in an OODB, assuming the implementation of a specified interface for interacting with an OODB. By using the interface, students can focus on object-oriented design and programming concepts associated with OODB concepts rather than the development of a user interface. Since the GUI uses the Extensible Markup Language (XML) for defining the database schema and data import/export, the use of the GUI provides the added benefit of demonstrating the manner in which XML interacts with database technology.
Schema closure is a property to guarantee that classes in a schema have not references to classes that are not included into it (external references). The existing methodologies solve this point including referenced c...
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ISBN:
(纸本)3540425276
Schema closure is a property to guarantee that classes in a schema have not references to classes that are not included into it (external references). The existing methodologies solve this point including referenced classes into the schema. In this paper, a new kind of schema closure (reduction closure) is put forward. Reduction closure is based on the transformation of classes with external references, removing these references to fulfil the schema closure 14 property. The main benefit of reduction closure is that it can be used as a method to simplify the external schema definition process, because explicit definition of derived classes for hiding external references is avoided. In addition, the explicit definition of derived classes to update the references to modified classes is also avoided. This closure algorithm is part of an external schema generation system for ODMG databases that we are developing, which is also briefly described in this paper.
The object-oriented programming language Java is an ideal companion to an object-oriented database system. This paper describes our approach to provide a seamless application programmer interface. it is based on a mod...
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ISBN:
(纸本)0818685859
The object-oriented programming language Java is an ideal companion to an object-oriented database system. This paper describes our approach to provide a seamless application programmer interface. it is based on a modular architecture with components for database engines, a communications protocol and a JAVA API faciltator: The open architecture is flexible, scalable and distributed in nature.
We propose an algorithm for executing transactions in objectorienteddatabases. The objectoriented database model generalizes the classical model of database concurrency control by permitting accesses to class and i...
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Most C++-based object-oriented databases have provided their own mechanisms for locking objects accessed in applications. However, some of these mechanisms make programmers spend a lot of time on locking objects and o...
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ISBN:
(纸本)0897918207
Most C++-based object-oriented databases have provided their own mechanisms for locking objects accessed in applications. However, some of these mechanisms make programmers spend a lot of time on locking objects and others are difficult to port on other systems. For alleviating these problems, this paper presents a mechanism for automatic object locking in those databases. In this locking mechanism, the lock for each object access in applications can be automatically determined at compile-time and then the lock can be automatically requested to the lock manager just before the object is accessed at run-time. Thus this mechanism is transparent to programmers and so it alleviates the impedance mismatch. As a result, programmers can spend less time on lockings and more time on specific application problems, and thus the productivity of application development can improve. Since this mechanism is independent of operating systems and lock managers, it can be easily ported on other C++-based object-oriented databases.
Much of the work in query optimization in object-oriented database is devoted to finding efficient ways of path traversais expressed in a query. In the environment where a query involves classes distributed across sev...
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In this paper, some unique features of fuzzy object-class relationships, which do not occur in classical object-oriented databases, are investigated. We identify direct object-class relationship, indirect object-class...
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ISBN:
(纸本)9780769534985
In this paper, some unique features of fuzzy object-class relationships, which do not occur in classical object-oriented databases, are investigated. We identify direct object-class relationship, indirect object-class relationship, and arbitrary object-class relationship in fuzzy object-oriented databases. In particular, soft computing methods are developed in the paper to quantitatively determine resemblance object-class relationships. The strategies to resolve the conflicts that an object belongs to multiple classes with different membership degrees simultaneously are hereby introduced
It has long been recognized that the “part” relation is an extremely useful modeling tool. This is especially true in areas such as manufacturing, design, graphics, and document processing. In this paper, we present...
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When implementing a multilevel security policy for object-oriented databases (OODBs), several aspects have to be investigated. One of these aspect is the design of multilevel OODBs. In an OODB, data are organized in a...
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ISBN:
(纸本)3540650040
When implementing a multilevel security policy for object-oriented databases (OODBs), several aspects have to be investigated. One of these aspect is the design of multilevel OODBs. In an OODB, data are organized in a complex structure built using different constructs (classes, objects, attributes, links...). Therefore, a first problem is to determine what constructs of the object-oriented model should be associated with a security level. A second problem is then to define semantics for each assignment of a security level to an object-oriented construct. While assigning the security levels, we have also to be careful with the inference problems which may occur due to the integrity constraints inherent in the object-oriented paradigm. Therefore, a last purpose of this paper is to define a set of general rules to cope with this problem.
This paper proposes a practical approach for designing object-oriented databases. Users start by describing their database applications with a semantic data model combined with a rule model. The semantic data model al...
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