Access support in object bases
Access support in object bases
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DOI：
10.1145/93597.98745
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发表时间：
1990-05
期刊：
影响因子：
--
通讯作者：
A. Kemper;G. Moerkotte
中科院分区：
文献类型：
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作者：
A. Kemper;G. Moerkotte
在这项工作中，访问支持关系被引入作为在面向对象数据库系统中优化查询处理的一种手段。总体思想是维护冗余的独立结构(与对象表示分离)，以存储在数据库查询中频繁遍历的对象引用。所提出的访问支持关系技术不再像在传统索引中那样被限制为将对象(元组)与原子值(属性值)相关联。相反，访问支持关系将对象彼此关联，并可以跨越可能包含集合值组件的引用链，以便支持涉及路径表达式的查询。对于给定的路径表达式，我们提出了访问支持关系的几种可选扩展，其中最好的扩展必须根据特定于应用的数据库使用配置文件来确定。建立了通道保障关系的成本分析模型及其应用。该分析成本模型尤其用于确定关于特定数据库配置和应用简档的最佳访问支持关系扩展和分解。
In this work access support relations are introduced as a means for optimizing query processing in object-oriented database systems. The general idea is to maintain redundant separate structures (disassociated from the object representation) to store object references that are frequently traversed in database queries. The proposed access support relation technique is no longer restricted to relate an object (tuple) to an atomic value (attribute value) as in conventional indexing. Rather, access support relations relate objects with each other and can span over reference chains which may contain collection-valued components in order to support queries involving path expressions. We present several alternative extensions of access support relations for a given path expression, the best of which has to be determined according to the application-specific database usage profile. An analytical cost model for access support relations and their application is developed. This analytical cost model is, in particular, used to determine the best access support relation extension and decomposition with respect to the specific database configuration and application profile.