数据源集成系统中全局模板的增量维护策略

异构数据源集成系统需要集成包括ＷＷＷ在内的各种数据源，一些半结构化数据对应的模式不仅量大且修改频繁，致使元数据的生成十分耗时．该文提出全局模板的增量维护策略．当局部模板发生变化时，利用局部模板的改变量（即模板增量）来计算全局模板的增量，进而修改全局模板．模板增量是传统实视图维护技术中增量概念的扩展，它不仅能描述对象结构特征的改变量，还能描述对象行为特征的改变量，易于表达各种数据源的模式变化.

Incremental Maintenance of Global Templates in Heterogeneous Data Integration System

A heterogeneous data integration system can integrate semistructured data which usually have large and changeable metadata, and generation of metadata is very time consuming. The metadata of Versatile are expressed in the form of templates. An incremental strategy for maintenance of templates is proposed, which can update the templates based on the changes (or delta in this paper) of the template rather than regeneration of all the templates from scratch. Different from deltas used for traditional incremental maintenance of materialized views,template deltas are able to describe the differences between not only the structures but also the behaviors of objects.It can express the differences between templates in virious data sources more easily.