Data exchange: On the complexity of answering queries with inequalities
Data exchange: On the complexity of answering queries with inequalities
复制标题
数据交换：关于回答不等式查询的复杂性
DOI：
10.1016/j.ipl.2005.03.001
复制
发表时间：
2005
期刊：
影响因子：
--
通讯作者：
A. Madry
中科院分区：
文献类型：
--
作者：
A. Madry
当我们需要将一种模式（源模式）下构造的数据（称为源实例）转换为另一种模式（目标模式）的实例（目标实例），尽可能准确地反映源实例，即满足源到目标的依赖性时，就会出现数据交换问题。当然，在大多数情况下，某个特定问题对应有许多有效的目标实例——我们可以将该问题的解决方案视为由所有可能的有效目标实例组成的不定数据库。因此，我们可以将不完整数据库理论中使用的某些答案的概念应用于数据交换中查询回答的语义，即我们只关注那些满足源到目标依赖性的每个目标实例中存在的肯定答案。在本文中，我们考虑存在布尔查询和本地视图（LAV）设置，这是一般数据交换问题设置的广泛使用的特殊情况。
The data exchange problem arises when we require data (called source instance) structured under one schema (source schema) to be translated into an instance (target instance) of a different schema (target schema), reflecting the source instance as accurately as possible, ie satisfying source-to-target dependences. Of course, in most cases there are many valid target instances corresponding to a particular problem-we can think of the solution of this problem as an indefinite database consisting of all possible target instances that are valid. So we can adapt the notion of certain answers used in the theory of incomplete databases for the semantics of query answering in data exchange, ie we focus only on those positive answers that hold in every target instance that satisfies the source-to-target dependences. In this paper we consider existential Boolean queries and the local-as-view (LAV) setting, which is a widely used, special case of the general data exchange problem setting.