object orientation offers a more direct and natural representation of real-world problems. object-oriented programming techniques enable the development of extensible and reusable modules. Combining the object-orien...
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object orientation offers a more direct and natural representation of real-world problems. object-oriented programming techniques enable the development of extensible and reusable modules. Combining the object-oriented contents of abstract data typing, inheritance, and object identity with database capabilities, such as persistence, transactions, concurrency, and query, results in powerful systems called object-oriented databases. These databases have become the dominant post-relational database management system and are a necessary evolutionary step toward the more powerful intelligent databases. Intelligent databases tightly join database and object-oriented technologies with artificial intelligence, information retrieval, and multimedia data manipulation techniques. Intelligent databases, along with intelligent database engines, are the most important component of future systems.
Query languages are an important component of any data management system. Therefore, recent object-oriented DBMS's provide (or plan to provide) some associative query capabilities. Because of the increased complex...
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Query languages are an important component of any data management system. Therefore, recent object-oriented DBMS's provide (or plan to provide) some associative query capabilities. Because of the increased complexity of the data model, designing a suitable query language raises new issues. In this paper, we describe how the characteristics of an object-oriented data model, such as object identity, complex object structure, methods, and class hierarchies, have an impact on the design of a query language. We also point out major differences with respect to relational query languages.
Query languages designed for traditional database systems, such as the relational model, generally support set operations. However, the semantics of these set operations are not adequate for richer data models of newl...
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Query languages designed for traditional database systems, such as the relational model, generally support set operations. However, the semantics of these set operations are not adequate for richer data models of newly developed object-based database systems that include object-oriented and semantic data modeling concepts. The reason is that precise semantics of set operations on complex objects require a clear distinction between the dual notions of a set and a type, both of which are present in the class construct found in object-based data models. In fact, class creation by set operations has largely been ignored in the literature. Our paper fills this gap by presenting a framework for executing set theoretic operations on the class construct. The proposed set operations, including set difference, union, intersection and symmetric difference, determine both the type description of the derived class as well as its set membership. For the former, we develop inheritance rules for property characteristics such as single-valued versus multivalued and required versus optional. For the latter, we borrow the object identity concept from data modeling research. Our framework allows for property inheritance among classes that are not necessarily IS-A related.
This paper presents an environment and a methodology for the design and rapid prototyping of data-intensive software applications;i.e., applications which perform substantial retrieval and update activity on persisten...
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This paper presents an environment and a methodology for the design and rapid prototyping of data-intensive software applications;i.e., applications which perform substantial retrieval and update activity on persistent data. In the proposed approach, the application is formally specified using Logres, a database language which combines object-oriented data modeling and rule-based programming. These specifications are translated into Algres, an extended relational algebra, thus yielding a rapid executable prototype. Finally, Algres programs embedded into a conventional programming language interface may be converted to conventional programs operating on a commercial relational system. This methodology helps automate the conversion from declarative requirements to imperative code, performing several tasks fully automatically and reducing the probability of human errors, while integrity constraints and application specifications are expressed in a declarative language, at a very high level of abstraction.
The integration of views and schemas is an important part of database design and evolution and permits the sharing of data across complex applications. The view and schema integration methodologies used to date are dr...
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The integration of views and schemas is an important part of database design and evolution and permits the sharing of data across complex applications. The view and schema integration methodologies used to date are driven purely by semantic considerations, and allow integration of objects only if that is valid from both semantic and structural view points. We discuss a new integration method called structural integration that has the advantage of being able to integrate objects that have structural similarities, even if they differ semantically. This is possible by using the object-oriented Dual Model which allows separate representation of structure and semantics. Structural integration has several advantages, including the identification of shared common structures that is important for sharing of data and methods.
The paper describes a CIM system designed to meet the needs of a Czechoslovak industrial company. After a brief analysis of the particular system, general considerations on software development and rapid prototyping a...
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The paper describes a CIM system designed to meet the needs of a Czechoslovak industrial company. After a brief analysis of the particular system, general considerations on software development and rapid prototyping are presented. Software engineering and artificial intelligence points of view are discussed.
The architecture of the open object-oriented database (OODB) management system, its requirements, and its computational model, which builds database functionality as an extensible collection of transparent extensions ...
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The architecture of the open object-oriented database (OODB) management system, its requirements, and its computational model, which builds database functionality as an extensible collection of transparent extensions to existing programming languages, are described. The way in which open OODB's system architecture is decomposed into a kernal meta-architecture and a collection of modules implementing specific behavioral extensions is discussed. The potential risks of the open OODB architecture are reviewed
In the new applications such as OIS, CAD/CAM, and AI, it is required to support not only fixed Is-A and Part-Of relationships but also various dynamic relationships including complicate constraints. However, existing ...
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An approach for supporting physical independence in object Database Servers is proposed in this paper. While in current implementations the strategy for storing data objects reflects the logical object definitions, a ...
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This paper describes a meta-programmed approach for merging class associations during schema integration in a logically heterogeneous object-oriented database environment. Association merging represents an important p...
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