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Model-based Global Query System
An
integrated enterprise information management system must be able to (1)
support end users needs in retrieving information at a global level and
(2) facilitate application programs to access, aggregate, and update information
maintained in multiple local systems.
Towards query formulation, on-line intelligence empowers the user interface
to provide assistance in the articulationas well as allow for high-level,
intuitive representation of queries. Specifically, for the articulation
of queries, the system would utilize its knowledge on the enterprise information
resources (or, metadata; including information models, implementation
models and business and operating rules) to alleviate semantic ambiguity,
facilitate logical analysis, and enhance adaptive construction during
the formulation of queries.
Similarly, the representation itself could accommodate heterogeneity
in local models across the enterprise (through, e.g., the knowledge on
data equivalence), without having to impose a single view (e.g., an "integrated
schema" of all databases) for all users to comply by. Making use
of the metadata, model-based global query system shown here accomplishes
the following:
- query optimization, by decomposing the global query into optimal local
queries, taking into account both semantics and performance;
- query translation, i.e., the local queries are then coded in their
respective data manipulation languages; and finally
- result integration: results from local systems are assembled to answer
the global query.
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