The paper presents concepts and ideas underlying an approach for constraint management in VLSI design database applications and designs flows. In this approach constraints are defined as scripts of EVA strongly typed ...
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ISBN:
(纸本)1932415270
The paper presents concepts and ideas underlying an approach for constraint management in VLSI design database applications and designs flows. In this approach constraints are defined as scripts of EVA strongly typed scripting language and stored in meta-databases called check catalogue. Interaction of applications with check catalogue is supported by subsystem of DBMS called Checker Frame-work. Checker Frame-work provides facilities for creation, modification and deletion of the constraints and has a several features that enhance the constraint management in database applications.
In this paper we propose a set-oriented rule-based method definition language for object-orienteddatabases. Most existing object-oriented database systems exploit a general-purpose imperative object-oriented programm...
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In this paper we propose a set-oriented rule-based method definition language for object-orienteddatabases. Most existing object-oriented database systems exploit a general-purpose imperative object-oriented programming language as the method definition language. Because methods are written in a general-purpose imperative language, it is difficult to analyze their properties and to optimize them. Optimization is important when dealing with a large amount of objects as in databases. We therefore believe that the use of an ad hoc, set-oriented language can offer some advantages, at least at the specification level. In particular, such a language can offer an appropriate framework to reason about method properties. In this paper, besides defining a set-oriented rule-based language for method definition, we formally define its semantics, addressing the problems of inconsistency and non-determinism in set-oriented updates. Moreover, we characterize some relevant properties of methods, such as conflicts among method specifications in sibling classes and behavioral refinement in subclasses. Copyright (C) 2003 John Wiley Sons, Ltd.
Active object-orienteddatabase management systems incorporate, object-orienteddatabase technology and active mechanisms such as event-condition-action rules (ECA-rules). SAMOS has been among the first representative...
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Active object-orienteddatabase management systems incorporate, object-orienteddatabase technology and active mechanisms such as event-condition-action rules (ECA-rules). SAMOS has been among the first representatives of this class of systems. During the development of SAMOS, numerous then open research questions have been addressed. In this paper, we present a "historical" perspective of the SAMOS project and report on lessons and experiences we have gained in the project. We identify requirements, present feasible solutions, and report on experiences we have drawn from this project. In particular, we describe the rule model of SAMOS;which represents a smooth integration of ECA-rules into an object-oriented data model. We also discuss the implementation and architecture of the SAMOS prototype on top of a passive object-orienteddatabase management system (OODBMS). Furthermore, we report on performance and usability issues. In order to analyze performance, we have developed a benchmark;we discuss the experiences (and improvements) we have made by running the benchmark on SAMOS and by comparing the results to those obtained for other systems. Usability issues have been investigated with respect to tool support for designing SAMOS applications and analyzing rule systems. Finally, we discuss our experiences in implementing SAMOS and the conclusions we have drawn for the implementation of other types of event-based persistent systems as well as a development method for active systems in general. (C) 2002 Elsevier Science Ltd. All rights reserved.
Concurrency control schemes for object-oriented database systems (OODBSs) used in the area of performance-critical applications should increase the degree of concurrency and decrease locking overhead in order to offer...
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Concurrency control schemes for object-oriented database systems (OODBSs) used in the area of performance-critical applications should increase the degree of concurrency and decrease locking overhead in order to offer maximum performance. However, most commercially available OODBSs use conventional concurrency control schemes that never exploit the rich semantics of object-oriented data model, thus fail to offer better performance. In this paper, we propose a concurrency control scheme for OODBSs, called in-place semantic multigranularity locking (ISMGL), that not only exploits semantics regarding methods to enhance the concurrency degree, but also utilizes multigranularity locking rules to decrease locking overhead. The novel aspect of ISMGL is that it combines conventional multigranularity locking and nested transaction model with utilizing commutativity of methods. Our concurrency control scheme is applicable for realistic OODBSs in the presence of complex objects with shared subobjects. Lastly, we evaluate the performance of ISMGL by using a simulation study.
ROL is a deductive object-orienteddatabase system that has been implemented at the University of Regina. It provides a uniform rule-based declarative language for defining, manipulating and querying databases, which ...
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ROL is a deductive object-orienteddatabase system that has been implemented at the University of Regina. It provides a uniform rule-based declarative language for defining, manipulating and querying databases, which integrates important features of both deductive databases and object-orienteddatabases. It supports object identity, complex objects, classes, class hierarchies, multiple inheritance with overriding and blocking, and schema definition. It also supports structured values such as functor objects and sets, treating them as first class citizens, and providing powerful mechanisms for representing both partial and complete information about sets. This paper describes its design and implementation. An important novel feature of the implementation is that it combines top-down and bottom-up evaluation strategies and automatically selects a strategy based on the nature of the query and data in the database.
In this paper we extend the ODMG object data model with composite objects. A composite object is an object built by aggregating other component objects. Exclusiveness and dependency constraints, as well as referential...
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In this paper we extend the ODMG object data model with composite objects. A composite object is an object built by aggregating other component objects. Exclusiveness and dependency constraints, as well as referential integrity, can be associated with composition relationships among objects. Our composite object model is developed in the framework of the ODMG objectdatabase standard data model, but can be used in both object-oriented and object-relational databasesystems. In the paper, we propose a language for defining composite objects and we define the semantics of update operations on composite objects.
In this paper we extend the ODMG object data model with composite objects. A composite object is an object built by aggregating other component objects. Exclusiveness and dependency constraints, as well as referential...
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ISBN:
(纸本)9781581130058
In this paper we extend the ODMG object data model with composite objects. A composite object is an object built by aggregating other component objects. Exclusiveness and dependency constraints, as well as referential integrity, can be associated with composition relationships among objects. Our composite object model is developed in the framework of the ODMG objectdatabase standard data model, but can be used in both object-oriented and object-relational databasesystems. In the paper, we propose a language for defining composite objects and we define the semantics of update operations on composite objects.
object-oriented database systems are designed to meet the requirements of advanced database applications such as computer-integrated manufacturing, These requirements may evolve in the course of time and may require t...
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object-oriented database systems are designed to meet the requirements of advanced database applications such as computer-integrated manufacturing, These requirements may evolve in the course of time and may require the migration of the database application from one object-orienteddatabase system to another, Traditional migration approaches for relational databasesystems fail when applied to object-oriented database systems. The goal of this paper is to fill this gap. The paper describes a framework for the migration of object-orienteddatabase applications, Our approach is based on a detailed analysis of the involved databasesystems, of the application's database requirements, and of the resources available for the database migration. We illustrate our framework by means of a case study, which is migrating an electronic planning board system from the object-orienteddatabase system ONTOS to objectStore.
A seamless approach to the incremental design and reuse of object-oriented methods and query specifications is presented, We argue for avoiding or minimizing the effort required for manually reprogramming methods and ...
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A seamless approach to the incremental design and reuse of object-oriented methods and query specifications is presented, We argue for avoiding or minimizing the effort required for manually reprogramming methods and queries due to schema modifications, and demonstrate how the role of polymorphic reuse mechanisms is exploited for enhancing the adaptiveness of database programs against schema evolution in an object-orienteddatabase. The salient features of our approach are the use of propagation patterns and a mechanism for propagation pattern refinement Propagation patterns are employed as an interesting specification formalism for modeling operational requirements. They encourage the reuse of operational specifications against the structural modification of an object-oriented schema. Propagation pattern refinement is suited for the specification of reusable operational modules. It promotes the reusability of propagation patterns toward the operational requirement changes. This approach has a formal basis and emphasizes structural derivation of specifications. The main innovations are in raising the level of abstraction for behavioral schema design, and for making possible the derivation of operational semantics from structural specifications. As a result, both the modularity and reusability of object-oriented schemas are increased.
To effectively model complex applications in which constantly changing situations can be represented, a database system must be able to support the runtime specification of structural and behavioral nuances for object...
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To effectively model complex applications in which constantly changing situations can be represented, a database system must be able to support the runtime specification of structural and behavioral nuances for objects on an individual or group basis. This paper introduces the role mechanism as an extension of object-orienteddatabases to support unanticipated behavioral oscillations for objects that may attain many types and share a single object identity. A role refers to the ability to represent object dynamics by seamlessly integrating idiosyncratic behavior, possibly in response to external events, with pre-existing object behavior specified at instance creation time. In this manner, the same object can simultaneously be an instance of different classes which symbolize the different roles that this object assumes. The role concept and its underlying linguistic scheme simplify the design requirements of complex applications that need to create and manipulate dynamic objects.
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