In a network of autonomous cooperating agents, complex distributed objects can be shared and exchanged. The novel feature presented in this paper is handling complex distributed objects, that we claim to be essential ...
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In a network of autonomous cooperating agents, complex distributed objects can be shared and exchanged. The novel feature presented in this paper is handling complex distributed objects, that we claim to be essential for cooperating teams of engineers e.g. in CIM, and in an environment that supports the integration of a group of expert systems. A model is presented here for the creation, retrieval, and modification of complex objects that are distributed in a federation of cooperating agents. The information that agents are willing to share with others in the federation is uniformly represented as inter-related objects. This defines a distributed object graph that spans over the entire federation of agents. Complex objects form a connected subgraph of this distributed object graph. To support safe cooperation and sharing of complex objects, while preserving agents’ autonomy, agents can bilaterally negotiate the access rights and deletion policies on distributed complex objects and when necessary these rights are propagated. Since the access rights are negotiated among agents, and not imposed by a central authority, the autonomy of each agent is fully maintained. To enable application programs to define and retrieve a complex object as a single entity, a linearization mechanism is introduced in the paper. The model described here has been developed as a part of the PEER system. PEER is a federated objectbase, designed and implemented as part of the Archon abstract machine, which provides an environment for the integration of heterogeneous cooperating expert systems.
Collection join queries are join queries based on collection attributes (i.e. non-atomic attributes), which are common in object-oriented databases. We have identified three different kinds of collection join queries,...
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Collection join queries are join queries based on collection attributes (i.e. non-atomic attributes), which are common in object-oriented databases. We have identified three different kinds of collection join queries, namely;cullection-equijoin,collection-intersectjoin, andsub-collectionjoin. In this paper, we propose parallel join algorithms for these three collection join query types based on a combination of sort and hash methods, which we callparallel sort-hash, collection join algorithms. The proposed join algorithms play an important role in parallel object-oriented query processing, due to their superiority over the conventional join methods which are usually in a form of relational division, and also the inefficiency of the original join predicate processing. In our implementation of these algorithms on a shared-memory machine, we show that the combination between sort and hash methods is proven to be better than the conventional sort-merge and nested-loop based parallel join processing
An object-oriented database is represented by a set of classes connected by their class inheritance hierarchy through superclass and subclass relationships. An object-oriented database is suitable for capturing more c...
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DBface is a toolkit for designing interfaces to object-oriented databases. It provides users with a set of tools for building custom interfaces with minimal programming. This is accomplished by combining techniques fr...
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DBface is a toolkit for designing interfaces to object-oriented databases. It provides users with a set of tools for building custom interfaces with minimal programming. This is accomplished by combining techniques from User Interface Management Systems (UIMS) with a built-in knowledge about the specific kinds of techniques used by object-oriented databases. DBface allows users to create graphical constructs and interactive techniques by taking advantage of an object-oriented database environment and tools. Not only can database tools be used for creating an interface, but information about the interface being built is stored within a database schema and is syntactically consistent with all other schema information. Thus, an interface can deal with data and schema information, including information about another interface. This allows for easy reusability of graphical constructs such as data representations.
This talk will outline the principles, the architecture and the potential target applications of a Deductive and object-oriented Database System (DOOD). Such systems combine the novel functionalities (relying on the a...
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With the rapid development of the Internet, XML (Extensible Markup Language) is increasingly gaining acceptance as a medium for integrating and exchanging data. Meanwhile, object-oriented database has a strong ability...
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With the rapid development of the Internet, XML (Extensible Markup Language) is increasingly gaining acceptance as a medium for integrating and exchanging data. Meanwhile, object-oriented database has a strong ability to store data, XML can benefit greatly and specifically from database support and object-oriented database management system. Consequently, it is significant to exchange data from object-oriented database to XML. In particular, taking spatiotemporal information existing in many practical applications into consideration, we study the spatiotemporal data models and the problem of exchanging spatiotemporal data from object-oriented database to XML. In order to find an XML Schema which is the best description of the existing object-oriented database, we propose a comprehensive approach to focus on a set of mapping functions to accomplish the transformation of spatiotemporal data.
object-oriented database systems (OODBs) need efficient support for manipulation of complex objects. In particular, support of queries involving evaluations of set predicates is often required in handling complex obje...
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Logres is a new-generation database system integrating features from deductive and object-oriented databases [1, 2, 3, 4, 5]. The data model of Logres supports structural and semantic complexity through a rich collect...
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Since the development of QBE, over fifty visual query languages have been proposed to facilitate easy database access. Although these languages have introduced some very useful paradigms, a number of these have some s...
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Index structures are often used to support search operations in large databases. Many advanced database application domains such as spatial databases, multimedia databases, temporal databases, and object-oriented data...
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ISBN:
(纸本)0909925836
Index structures are often used to support search operations in large databases. Many advanced database application domains such as spatial databases, multimedia databases, temporal databases, and object-oriented databases, call for index structures that are specially designed and tailored for the domains. Interestingly, in each of these domains, we find methods that are based on one distinct structure - the B-tree. Invented some thirty years ago, the B-tree has been challenged repeatedly, but has retained its competitiveness. In this paper, we first give a quick review of B-trees. We then present its adaptations to various domains. For each domain, we present representative B-tree-based structures and their search operations. We conclude that the B-tree is truly an ubiquitous structure that has stood the test of times with wide acceptance in many domains.
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