Object Exchange Model
In order for mediators and wrappers to exchange data, they need to use a common data representation.
Since the structure of data can vary among queries as well as among sources were defined following requirements:
- The representation must be flexible enough to handle data from different types of sources.
- The representation must be capable to adapting to a dynamic environment where data sources can be added or removed at any time
- The representation must be independent of how data is stored in the underlying data sources
- The representation must be capable of representing objects which may or may not have data available for every attribute in every instance.
- The representation must facilitate data integration.