Design Engineers frequently re-use or adapt old designs. Currently, this process is undertaken manually, albeit with the assistance of CAD and analysis software. Using object-oriented databases, the DESCRIBE (DEsign S...
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ISBN:
(纸本)0818683082
Design Engineers frequently re-use or adapt old designs. Currently, this process is undertaken manually, albeit with the assistance of CAD and analysis software. Using object-oriented databases, the DESCRIBE (DEsign System to support Concurrent Re-use of data in Building and Engineering Design) project concerns the creation of a system that allows the storage of design artefacts as discrete objects using object 'wrappers'. DESCRIBE employs versioning and configuration management support and has art intuitive user interface. To give the work a practical focus, we are considering the domain of bridge design.
To avoid OID index retrieval becoming a bottleneck, efficient buffering strategies are needed to minimize the number of disk accesses. In this paper, we develop analytical cost models which we use to find optimal size...
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Performance in parallel database systems very much depends on how data is placed on a network of processing elements. In designing a data placement method, particularly for high performance parallel object-oriented da...
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ISBN:
(纸本)3540644431
Performance in parallel database systems very much depends on how data is placed on a network of processing elements. In designing a data placement method, particularly for high performance parallel object-oriented databases, two major factors that most of the time contradict each other, particularly minimizing communication cost and maintaining load balance, must be taken in account. Our experiments' results show that it is not feasible to trade I/O balancing with low communication costs, although these two factors are critical. Therefore, an ideal data placement method must feature a reasonable I/O balancing combined with low communication whenever possible, not the other way round.
The multiobject mechanism is a pertinent way to implement specialization in an object database and differs from the classical mechanism used in most object-oriented database systems. It supports multiple instantiation...
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We show how model extensibility of object-oriented data management systems can be achieved through the combination of a high-level core object data model and an architecture designed with model extensibility in mind. ...
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ROL is a strongly typed deductive object-oriented database language. It integrates many important features of deductive databases and object-oriented databases. However, it is only a structurally object- oriented lang...
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The current fashion for pushing toward objectoriented (Oh-Oh!) methodologies, tools (manage objects not data), and terminology (business objects design) has obscured the real advantages of object-orientation and obje...
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One of the differences between relational and object-oriented databases (OODB) is that attributes in OODB can of a collection type (e.g. sets, lists, arrays, bags) as well as a simple type (e.g. integer, string). Cons...
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ISBN:
(纸本)3540649522
One of the differences between relational and object-oriented databases (OODB) is that attributes in OODB can of a collection type (e.g. sets, lists, arrays, bags) as well as a simple type (e.g. integer, string). Consequently, explicit join queries in OODB may be based on collection attributes. One form of collection join queries in OODB is collection-intersect join queries, where the joins are based on collection attributes and the queries check for whether there is an intersection between the two join collection attributes. We propose two algorithms for parallel processing of collection-intersect join queries. The first one is based on sort-merge, and the second is based on hash. We also present two data partitioning methods (i.e. simple replication and "divide and partial broadcast") used in conjunction with the parallel collection-intersect join algorithms. The parallel sort-merge algorithm can only make use of the divide and partial broadcast data partitioning, whereas the parallel hash algorithm may have a choice which of the two data partitioning to use.
Client applications usually hold (derived) subsets of the database contents under their control. The incremental maintenance of such externally materialized views is an importîmt open problem. In addition to some...
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A commonly followed approach in database design is to collect user views on the database and to develop the conceptual schema of the database by integrating these views. The design of object-oriented databases involve...
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