Constraint-based Query Distribution Framework for an Integrated Global Schema

TL;DR

This paper presents a constraint-based framework for distributing queries over a global schema to efficiently query heterogeneous distributed data sources, utilizing XML-based systems for query formulation and result integration.

Contribution

It introduces a novel global query distribution framework that leverages constraints for source selection and query optimization in heterogeneous data environments.

Findings

Effective source selection using constraints

Improved query optimization in distributed systems

XML-based integration of local query results

Abstract

Distributed heterogeneous data sources need to be queried uniformly using global schema. Query on global schema is reformulated so that it can be executed on local data sources. Constraints in global schema and mappings are used for source selection, query optimization,and querying partitioned and replicated data sources. The provided system is all XML-based which poses query in XML form, transforms, and integrates local results in an XML document. Contributions include the use of constraints in our existing global schema which help in source selection and query optimization, and a global query distribution framework for querying distributed heterogeneous data sources.