发明申请
US20100306219A1 Cache-Based Predicate Handling For Queries On XML Data Using Uncorrelated Path-Based Row Sources
有权
基于缓存的谓词处理使用不相关的基于路径的行源的XML数据查询
- 专利标题: Cache-Based Predicate Handling For Queries On XML Data Using Uncorrelated Path-Based Row Sources
- 专利标题(中): 基于缓存的谓词处理使用不相关的基于路径的行源的XML数据查询
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申请号: US12474124申请日: 2009-05-28
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公开(公告)号: US20100306219A1公开(公告)日: 2010-12-02
- 发明人: Balasubramanyam Sthanikam , Sivasankaran Chandrasekar , Sam Idicula , Nipun Agarwal
- 申请人: Balasubramanyam Sthanikam , Sivasankaran Chandrasekar , Sam Idicula , Nipun Agarwal
- 主分类号: G06F17/30
- IPC分类号: G06F17/30 ; G06F7/00
摘要:
The approaches described herein provide an efficient way to process certain kinds of queries that retrieve XML data stored in an object-relational database. An XML query may include a predicate condition that joins two row sources. One or both of the row sources required for predicate evaluation may be path-based; that is, consume and produce rows of XMLType data. Such a path-based row source may be modified to use the predicate condition to filter the rows it generates so that only rows satisfying the predicate condition need to be further processed. A small cache structure introduced into the path-based row source may be used to optimize the evaluation of the predicate row. Once populated with row data, the cache structure may be reorganized to optimize the performance of predicate evaluation.