异构数据源集成系统中能力对象集成模型及代数

A Data Model and Algebra for Capability Object Integration in Heterogeneous Data Integration Systems

异构数据源集成系统中,参与集成各数据源的查询处理能力有自身特殊的限制,导致中介器支持的查询类型变得复杂。提出一种便于异构数据源集成的公共能力对象数据模型———COIM对象模型,在此基础上,进而定义数据源能力对象代数,给出基于局部数据源的能力对象构造集成系统中介器能力对象的方法。由于可以通过计算得到中介器能力对象,用户能够提前预知中介器支持的查询类型,从而直接构造可以执行的查询,减少查询提交的盲目性;同时中介器本身也可像数据源一样参与其它中介器的集成,集成方式变得更为灵活。

In heterogeneous data sources integration systems, there can be many special limited access patterns to access interface of data sources, i.e., binding patterns impose a restriction that one or more input attributes must have a binding, and also restrict the output attributes that are projected. Constrained by the expressiveness of the access interface, users often have difficulty in articulating a precise query over the data sources. In this paper, we propose a data model for data sources' capability object integration (COIM) to capture a rich variety of query-processing capabilities and present algebra to compute the set of mediator-supported queries based on the capability limitations of the sources they integrate. By computing mediator query capabilities and representing them in the same way as those of data sources, we enable mediators to be used by other mediators as well as other applications, and we also make it easier for end users to know in advance which mediator queries are feasible.