This paper deals with furnishing object-oriented database models with a paradigm of taxonomic reasoning, i.e., an inference capability characteristic of the knowledge representation systems developed within the KL-ONE...
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In this paper, a locking-based concurrency control scheme is presented for object-oriented databases (OODBs). It is designed for controlling accesses to class hierarchies, which is an important concept in OODBs. Based...
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ISBN:
(纸本)3540676279
In this paper, a locking-based concurrency control scheme is presented for object-oriented databases (OODBs). It is designed for controlling accesses to class hierarchies, which is an important concept in OODBs. Based on access frequency of each class, the proposed scheme incurs less locking overhead than the existing works, explicit locking and implicit locking, for any OODB environments. This paper also proves that the proposed scheme performs better than the existing schemes.
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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In this paper we present a framework and algorithms for method evolution handling in object-oriented databases. Two levels of granularity for method evolution ate described. The first level to the evolution of methods...
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ISBN:
(纸本)3540587861
In this paper we present a framework and algorithms for method evolution handling in object-oriented databases. Two levels of granularity for method evolution ate described. The first level to the evolution of methods in the context of the class inheritance hierarchy, and concerns the semantics of the polymorphism. The second level relates to the behavioural evolution in which the chain of calling relationships between methods is considered. A graph based approach is used to achieve such behavioural consistency in order to prevent the problems of run-time errors, side-effects, and to detect redundant methods and unexpected behaviours.
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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One of the central concepts in the field of object-oriented databases is object identity, which nicely captures mutability, sharing and cyclic structures. Although the concept is intuitively clear, its precise semanti...
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We describe a concurrent garbage collector (GC) for object-oriented databases. Our GC uses a new synchronization mechanism (mechanism that allows the GC to operate concurrently with ordinary users of the database), ca...
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ISBN:
(纸本)1558604707
We describe a concurrent garbage collector (GC) for object-oriented databases. Our GC uses a new synchronization mechanism (mechanism that allows the GC to operate concurrently with ordinary users of the database), called GC-consistent cuts. A GC-consistent cut is a set of virtual copies of database pages. The copies are taken at times such that an object may appear as garbage in the cut only if it is garbage in the system. Our GC examines the copies, instead of the real database, in order to determine which objects are garbage. GC-consistent cuts are easy to implement by already-existing code that implements consistent read-only transactions. Our GC scales up. Unlike other scalable GCs, it does not require the user to explicitely partition the database into loosely-connected subsets, and does not introduce code that must run all the time, hereby avoiding to slow down the system while the GC is not running.
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.
An overview of the current status in the area of formal technique of object database design is described in the article. It is discussed here, why relational normalization is not able to be easy used in object databas...
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ISBN:
(纸本)9781402087400
An overview of the current status in the area of formal technique of object database design is described in the article. It is discussed here, why relational normalization is not able to be easy used in objectdatabases. The article introduces various proposals of object normal forms and it brings own authors' evaluation in this area.
In this paper we present an algorithm which automatically discovers potential semantic object structures in a relation, which may be in non-2NF. This algorithm can be utilised in reverse engineering of relational sche...
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ISBN:
(纸本)3540411844
In this paper we present an algorithm which automatically discovers potential semantic object structures in a relation, which may be in non-2NF. This algorithm can be utilised in reverse engineering of relational schemas, data migration from relational to object database systems and database integration. The algorithm has been implemented, and we report on issues arising from this implementation including optimization techniques incorporated.
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