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.
A typed, object-oriented, temporal constraint system is presented. The constraint programming paradigm is based on temporal Horn clause logic. If differs from executable temporal logic programming paradigms in that it...
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This paper investigates an algorithm for semantic query optimization for object-oriented databases (OODBs). Semantic query optimization is accomplished by applying transformation rules that use semantic integrity cons...
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In this paper, formal relationships between classes of objects based on semantic data models (i.e. conceptual classes) and classes of objects based on object models (i.e system classes), are established. The proposed ...
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In this paper, formal relationships between classes of objects based on semantic data models (i.e. conceptual classes) and classes of objects based on object models (i.e system classes), are established. The proposed method starts from conceptual classes and generates system classes, This method can be employed to implement semantic data models on top of currently available objectoriented database systems. As a consequence, the database applications can be specified with the flexibility of a conceptual schema while the obtained implementation exploits the efficiency of an object-oriented database system. Both the correctness and the completeness of our method are demonstrated and a discussion on its complexity is provided.
This paper addresses the problem of method evolution in object-oriented databases. We propose a set of evolutionary operations that affect all parts of methods, the signature and the implementation. When a restructuri...
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This paper addresses the problem of method evolution in object-oriented databases. We propose a set of evolutionary operations that affect all parts of methods, the signature and the implementation. When a restructuring operation is applied to a schema, behavioral consistency is checked by constructing a proof of program correctness. Two levels of granularity for behavioral consistency are described. The first level relates to the evolution of methods in the context of class inheritance hierarchy and is concerned with the semantics of the polymorphism of methods. The second level relates to behavioral evolution in which the chain of calling relationships between methods is considered. Behavioral consistency is checked with a graph-based approach that deals with problems such as run-time type errors, side-effects, redundant methods, and unexpected behaviors.
The use of object database management systems in a NI altitude classification of applications is growing at a rapid pace in the mainstream world. objectdatabases bring another advantage for traditional client server ...
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ISBN:
(纸本)0818684828
The use of object database management systems in a NI altitude classification of applications is growing at a rapid pace in the mainstream world. objectdatabases bring another advantage for traditional client server applications in that they provide a client side cache for the most frequently accessed data accessed from the database. This client side cache provides tremendous benefits for multi-tier architectures, which must: utilize thin clients communicating with application servers. The extension of the database technology from the sewer to the client effectively provides the mechanism for building these multi-tier architectures in a scalable manner. The methodology for this implementation is diverse, bur the underlying technology for the application servers is the object database management system's managed client side cache.
In this paper we describe Kaleidoquery, a visual query language for objectdatabases with the same expressive power as OQL. We will describe the design philosophy behind the filter flow nature of Kaleidoquery and pres...
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In this paper we describe Kaleidoquery, a visual query language for objectdatabases with the same expressive power as OQL. We will describe the design philosophy behind the filter flow nature of Kaleidoquery and present each of the language's constructs, giving examples and relating them to OQL. The Kaleidoquery language is described independent of any implementation details, but a brief description of a 3D interface currently under construction for Kaleidoquery is presented. The queries in this implementation of die language are translated into OQL and then passed to the object database O2 for evaluation.
This paper describes the activities of object-oriented (OO) analysis that were implemented in order to obtain a high part representation level and to give sets of structured and hierarchical data to the Computer Aided...
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This paper describes the activities of object-oriented (OO) analysis that were implemented in order to obtain a high part representation level and to give sets of structured and hierarchical data to the Computer Aided Process Planning (CAPP) system. The OO modeling activities were carried out by using the object-oriented System Analysis (OOSA) method which allows careful specification of all the information contained inside the system. All the models used by this method have been described in detail to show how the OO database is defined and how it can be used by a generative CAPP system. The feature model proposed is defined by taking all the part information that;can be recognized and extracted from the Computer Aided Design (CAD) model into account. The result is the design of an OO database which allows the CAPP system to use manufacturing features to define machining operation sequences of 3D workpieces. The approach proposed is generic enough to integrate any geometrical forms which can be recognized and identified from the CAD system. Hole geometry is taken as an example to show the link between the step of OO analysis and the step of knowledge representation in the Expert System which has been used to generate machining cycles. The OO database presented makes up a real solution of CAD/CAPP/CAM integration by using feature modeling. (C) 1998 Elsevier Science Ltd. All rights reserved.
In the last few years, there has been a discernible shift in the system development paradigm from traditional, structured approaches to the object-oriented (OO) paradigm. Several organizations have begun to move towar...
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In the last few years, there has been a discernible shift in the system development paradigm from traditional, structured approaches to the object-oriented (OO) paradigm. Several organizations have begun to move towards distributed systems and OO development in an effort to exploit the benefits of distribution, coupled with the promise of efficient development. It is suggested that successful adoption of distributed object computing, will require careful attention to a number of issues, some of which include deployment and management of distributed OO systems. This article proposes a comprehensive scheme for effective distribution of OO applications over existing networks of computers. The proposed scheme exploits relevant features of OO systems and extends current data distribution research to identify and formalize appropriate design criteria and develop techniques for optimization of these criteria. The scheme consists of two levels. The first specifies procedures and algorithms that can be used to distribute OO systems across geographically dispersed locations. The second level formulates several performance criteria and an iterative decision support procedure. INSET: Facilitating object Distribution.
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