MDDQL : an ontology driven , multi - lingual query language and system for an integrated view of heterogeneous data sources .

Query languages and keywords based search engines are conventionally specified and implemented with the emphasis put on syntactic rules to which query typing and answering must be bound. MDDQL is a query language and system that operates on a semantic model in terms of a graph based ontology. As a software technology, MDDQL allows the meaning of/and associations between information to be known and processed at execution time at following levels: (a) driving the user to the construction of, as meaningful as possible, queries with an advanced concept-based search method, (b) resolving high level queries into various data source specific query statements. In addition, queries can be posed in more than one natural sub-language. The major goal behind this approach has been the simplification and scalability of both tasks: query construction, even within multi-lingual user communities, and addressing of a large number of possibly semantically heterogeneous data sources in a distributed environment.