【摘要】 以往的查询包含判断,并不是真正意义上的查询包含,而是一种被称为一致性包含的概念,一致性包含是查询包含的充分条件,而不是必要条件,而且一般的查询包含只考虑两个查询之间的包含关系,该文使用视图更新的方法判断多查询之间的包含关系,并且文章中涉及的视图更新是独立于具体方法的。在判断多查询之间的包含关系时,该文还用到了副的文字量。更多还原

【Abstract】 In the past,the methods for Query Containment checking do not check actually containment but another related property called uniform containment.The uniform containment is a sufficient but not necessary condition for containment.This paper uses a new approach which tackles Query Containment problems among multi queries by expressing them as a view updating problem,and the approach is independent of any view updating method.Particularly,this paper considers negative-derived literals.更多还原