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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We define a class of graphs that represent object-oriented databases. Queries, updates and restructurings in such databases are performed by transformation of these graphs. We therefore first define five transformatio...
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ISBN:
(纸本)9783540551218
We define a class of graphs that represent object-oriented databases. Queries, updates and restructurings in such databases are performed by transformation of these graphs. We therefore first define five transformation-operations on this graph-class. Then we define generic transformations as a natural generalization of the concept of BP-completeness, originally defined for the relational database model. Our main result states that the language consisting of the five transformation-operations expresses exactly the generic transformations.
This paper confirms the importance of the ability of managing a large number of managed objects to effectively manage a local fiber optical network. Four basic methods for storing managed objects in an objectoriented...
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This paper presents an approach for providing access control in OSQL, an object-oriented database language that supports, among others, user-defined abstract data types, multiple inheritance, and late binding. The aut...
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CQL++ is a declarative front end to the Ode object-oriented database. It combines a SQL-like syntax with the C++ class model. CQL++ provides facilities for defining classes, and for creating, querying, displaying, and...
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The concept of a trigger is central to any active database. Upon the occurrence of a trigger event, the trigger is “fired”, i.e, the trigger action is executed. We describe a model and a language for specifying basi...
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ISBN:
(纸本)0897915216
The concept of a trigger is central to any active database. Upon the occurrence of a trigger event, the trigger is “fired”, i.e, the trigger action is executed. We describe a model and a language for specifying basic and composite trigger events in the context of an object-oriented database. The specified events can be detected efficiently using finite *** integrate our model with O++, the database programming language for the ode object database being developed at AT&T Bell Labs. We propose a new Event-Action model, which folds into the event specification the condition part of the well-known Event-Condition-Action model and avoids the multiple coupling modes between the event, condition, and action trigger components.
In many engineering applications, changes to the state and/or structure of an object needs to be maintained over a period of time. Existing object-oriented data models allow such changes in the state (referred to as V...
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object-oriented databases are said to support evolution and incremental development. On the schema level, a firm restriction in this evolution is that it can only be done by evolving class hierarchies downwards by sub...
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In this paper, we address the problem of supporting more flexibility on the schema of object-oriented databases. We describe a general framework based on an object-oriented data model, where three levels of objects ar...
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Early work on reconfiguration of distributed applications was done as part of the Argus project at MIT. We review that work, examine the lessons that we learned, and relate our Argus experience to current plans for bu...
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