Mediator-based information system

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A mediator-based information system is an information system that combines several information sources through virtual integration . The central component of the system is a mediator (the corresponding design pattern is called a mediator ) who receives and answers queries to the overall system and communicates with the sources. A simple example of a mediator-based information system is a meta search engine .

In a mediator-based information system, the data is only stored in the sources. With each request, the sources are specifically addressed, so that ideally only the data need to be transmitted that is necessary to answer the request. For this, the data from the various sources must be standardized ( data cleansing , data fusion ) and summarized ( schema mapping ). Optimizing this process is difficult because it has to take place online for the most part (new with each request) and is very dependent on the capabilities of the sources. A fundamental problem is the speed: a request cannot be answered faster than the slowest source required for the answer. At the same time, a mediator-based information system is very flexible. In most cases, sources can be integrated dynamically and the failure of a source can be compensated for.

The draft takes place according to the top-down principle. The sources of a mediator-based information system are packed by wrappers and connected to the mediator.

See also