Template-Based Wrappers in TSIMMIS

Joachim Hammer, Hector Garcia-Molina, Svetlozar Nestorov, Ramana Yerneni, Marcus Breunig, Vasilis Vassalos


In order to access information from a variety of heterogeneous information sources, one has to be able to translate queries and data from one data model into another. This functionality is provided by so-called wrappers which convert queries into one or more commands/queries understandable by the underlying sources and transform the native results into a format understood by the application. In the TSIMMIS project, we have developed a wrapper implementation toolkit for quickly building wrappers on a variety of sources. Our toolkit is based on the concept of query templates that are declaratively specified by the wrapper implementor. Using this toolkit, the process of constructing a wrapper is greatly simplified to the point that wrappers for many sources can be implemented within a matter of days if not hours (a dramatic improvement from our earlier experience of building a wrapper for a new source over a period of months).