Traditional algorithms for optimizing the execution order of joins are no more valid when selections and projections involve methods and become very expensive operations. Selections and projections could be even more ...
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Traditional algorithms for optimizing the execution order of joins are no more valid when selections and projections involve methods and become very expensive operations. Selections and projections could be even more costly than joins such that they are pulled above joins, rather than pushed down in a query tree. In this paper, we take a fundamental look at how to approach query optimization from a top-down design perspective, rather than trying to force one model to fit into another. We present a graph model which is designed to characterize execution plans. Each edge and each vertex of the graph is assigned a weight to model execution plans. We also design algorithms that use these weights to optimize the execution order of operations. A cost model of these algorithms is developed. Experiments are conducted on the basis of this cost model. The results show that our algorithms are superior to similar work proposed in the literature.
A methodology is introduced for translating from methods in an object-oriented database to routines in a relational database. The approach consists of three steps. The first step is to translate method signature to Pe...
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A methodology is introduced for translating from methods in an object-oriented database to routines in a relational database. The approach consists of three steps. The first step is to translate method signature to Persistent Stored Modules signature. The second step is to translate method source language to (function/procedure) routine. The process includes Host Language, OSQL's Qualification, Query Translation, Update Transaction Translation, and objects inside object. The third step is to translate method invocation to routine invocation. According to this approach, object-oriented database methods can be translated to relational database routines that can be executed in the relational database environment assisted by a frame model and case statements listing all possible cases of binding conditions and actions. The significance of the finding is adding an open object-oriented interface on top of relational database system for database interoperability and in the development of an object-relational database management system.
The problem of building a large location table for physics objects occurs within a number of planned physics data management systems, like those that control reclustering and wide-area replication. To satisfy their ef...
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The problem of building a large location table for physics objects occurs within a number of planned physics data management systems, like those that control reclustering and wide-area replication. To satisfy their efficiency goals, these systems have to make local or remote replicas of individual physics objects, which contain raw or reconstructed data for a single event, rather than replicas of large run or n-tuple files. This replication implies the use of a table to resolve the logical, location independent object descriptor into a physical location where an object replica can be found, For modern physics experiments the table needs to scale to at least some 10(10) objects. We argue that such a table can be efficiently implemented by limiting the freedom of lookup operations, and by exploiting some specific properties of the physics data model. One specific viable implementation is discussed. (C) 2001 Elsevier Science B.V. All rights reserved.
There are only a few garbage collection algorithms that have been designed to operate over massive object stores. These algorithms operate at two levels, locally via incremental collection of small partitions and glob...
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ISBN:
(纸本)0769509649
There are only a few garbage collection algorithms that have been designed to operate over massive object stores. These algorithms operate at two levels, locally via incremental collection of small partitions and globally via detection of cross partition garbage, including cyclic garbage. At each level there is a choice of collection mechanism. For example, the PMOS collector employs tracing at the focal level and reference counting at the global level Another approach implemented in the Thor object database uses tracing at both levels. In this paper we present two new algorithms that both employ reference counting at the local level. One algorithm uses reference counting at the higher level and the other uses tracing at the higher level. An evaluation strategy is presented to support comparisons between these four algorithms and preliminary experiments are outlined.
In this paper, we report on the design and implementation of a multi-modal user interface of the virtual world database system (VWDB). The VWDB is currently under development at Ochanomizu University with the aim of r...
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ISBN:
(纸本)0769509967;0769509975
In this paper, we report on the design and implementation of a multi-modal user interface of the virtual world database system (VWDB). The VWDB is currently under development at Ochanomizu University with the aim of realizing a new generation database system for cyberspace applications. The system will be constructed bu integrating a virtual reality system and an object-oriented database system. Since the VWDB provides a virtual world as the user's database interface, the system must support a multi-modal database language with which users can interact with the VWDB database by means of gesture and voice. We introduce here an automata-based approach to designing the multi-modal manner. We identify a set of automata to characterize the multi-modal interaction and describe a semantic network approach for translating a multi-modal user input to an equivalent message to access and manipulate database objects.
Multidimensional raster data appears in many application areas, typically in the form of sampled spatial or spatio-temporal analogue data. Due to the data volume and correlations between neighbouring samples usually e...
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ISBN:
(纸本)3540425276
Multidimensional raster data appears in many application areas, typically in the form of sampled spatial or spatio-temporal analogue data. Due to the data volume and correlations between neighbouring samples usually encountered in this kind of data it has high potential for efficient compression, as can be seen by the wealth of specialized compression techniques developed for 2D raster images;other examples would be ID time series, 3D volumetric or spatiotemporal data, 4D spatio-temporal data or 5+D data typically found in OLAP data cubes. Efficiently handling this kind of data often requires compression, be it to reduce storage space requirements or transfer times over low-bandwidth media. In this paper we present the design of the generic, tile-based compression engine developed for this purpose and implemented in the multidimensional array DBMS RasDaMan.
The problem of building a large location table for physics objects occurs within a number of planned physics data management systems, like those that control reclustering and wide-area replication. To satisfy their ef...
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The problem of building a large location table for physics objects occurs within a number of planned physics data management systems, like those that control reclustering and wide-area replication. To satisfy their efficiency goals, these systems have to make local or remote replicas of individual physics objects, which contain raw or reconstructed data for a single event, rather than replicas of large run or n-tuple files. This replication implies the use of a table to resolve the logical, location independent object descriptor into a physical location where an object replica can be found, For modern physics experiments the table needs to scale to at least some 10(10) objects. We argue that such a table can be efficiently implemented by limiting the freedom of lookup operations, and by exploiting some specific properties of the physics data model. One specific viable implementation is discussed. (C) 2001 Elsevier Science B.V. All rights reserved.
When companies interchange information about individuals, privacy is at stake. On the basis of the purpose of the information interchange, rules can be designed for an agent (Alter-ego) to determine whether the reques...
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This paper discusses the design of an object-oriented system with business rules where the rules are treated as objects in their own right. The paper argues that an architecture-centric approach is essential in develo...
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ISBN:
(纸本)9729805024
This paper discusses the design of an object-oriented system with business rules where the rules are treated as objects in their own right. The paper argues that an architecture-centric approach is essential in developing any software system and puts forward a multi-tiered architecture for incorporating business rules in an object-oriented environment. In the architecture, rule objects are completely separate from the domain objects, promoting rule maintenance. No assumption is made about other layers such as the persistence layer, allowing domain objects to be stored in any manner such as in an object database, a relational database, a flat file, or in some other format. The architecture also lends itself to object distribution of both domain and rule objects using standards such as the Common object Request Broker Architecture.
The process of designing an object-oriented database schema consists of several phases. During the phase of abstract logical formalisation one of many possible abstract object-oriented database schemas must be chosen....
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