公开(公告)号：US06381616B1

公开(公告)日：2002-04-30

申请号：US09275704

申请日：1999-03-24

申请人： Gustav Per-Åke Larson ,  Weiye Zhang

发明人： Gustav Per-Åke Larson ,  Weiye Zhang

IPC分类号： G06F1200

CPC分类号： G06F17/30439 ,  G06F17/30442 ,  G06F17/30569 ,  Y10S707/99934 ,  Y10S707/99952

摘要： A system and method for modifying or converting predicates involving a comparison with a string constant in a query is provided so that the predicates can be evaluated by an external or remote source that uses a different collating sequence, thereby effectively reducing the amount of data sent over a network. Techniques for predicate simplification are also provided for complex predicates. Although it is desirable that the converted predicate precisely match the original predicate, it is not necessary; an imprecise predicate that selects a superset of the target rows is sufficient. Thus, techniques for imprecise conversion are also provided. For an imprecise conversion, the original query is further evaluated against the obtained superset to obtain the final result, whereas for a precise conversion, the returned set is the required set, and no further evaluation is needed.

摘要翻译： 提供了用于修改或转换涉及与查询中的字符串常量进行比较的谓词的系统和方法，以便可以由使用不同对照序列的外部或远程源来评估谓词，从而有效地减少发送的数据量 一个网络。 还提供了谓词简化的技术，用于复杂谓词。 虽然转换谓词与原始谓词精确匹配是合乎需要的，但并不是必需的; 选择目标行的超集的不精确的谓词就足够了。 因此，还提供了用于不精确转换的技术。 对于不精确的转换，原始查询将根据获取的超集进行进一步评估，以获得最终结果，而对于精确转换，返回的集合是所需集合，不需要进一步评估。