Le Select

Le Select is a framework prototype for accessing data of heterogeneous nature and for invoking data processing program over Internet/intranet environments" [1]

Le Select is a middleware software system that was designed with the intention of providing an organised platform from which to access distributed data and software resources. Unlike data warehouses that attempt to collect data into a central location, usually in a single format or data structure, Le Select is a mediator that aims to provide connection to data.

System architecture

Le Select is based on a distributed computing system and has a fully distributed architecture. There is no Le Select global repository and no global schema. When data is published on Le Select it is viewed by users as tuples in a relational table, regardless of the native data format which could be a flat file or a spreadsheet. Wrappers are software modules used by Le Select to translate data from native format into the relational format that is viewed by users. They also contain information about how to locate data on a server and how to access it and are formed by a set of Java Classes with additional XML definition files. They are designed so that wrappers that serve similar purposes can be re-written, rather than a developer having to start from scratch.

Because Le Select is based on a fully distributed system architecture, a program can run on one Le Select server whilst using data from another server. The system sends the data to the server where the program is running, coordinates its execution and sends back the results to the client as relational table.

Viewing data through Le Select

A user can view Le Select data through a standard Web-browser, in the form of tuples in a relational database. Additional capabilities include the provision of SQL search abilities.

Summary

Le Select is a form of middleware software that is based on a fully distributed system architecture. It allows users to publish and consult a wide range of data that can be queried and accessed remotely, via the Internet

External links

• http://www-smis.inria.fr/dataFiles/B01.pdf
• http://www.inria.fr/valorisation/rencontres/web-semantique/demonstrations/le-select.pdf

References

• [1] Moura, A.M.; M. Victorino and A. Tanaka, 2002. Combining Mediator and Data Warehouse Technologies for Developing Environmental Decision Support Systems. In, M.J. Egenhofer and D.M. Mark (Eds.) GIScience 2002, LNCS 2478, Springer-Verlag, Berlin, pp. 196–208.
• [2] INRA: The Ecobase Project: Database and Web Technologies for Environmental Information Systems (Available Online From: http://www-smis.inria.fr/dataFiles/B01.pdf)