This document discusses data schema integration, which involves identifying correspondences between elements in different data schemas that describe the same real-world concepts, and resolving conflicts between the schemas. The integration process includes schema transformation to homogenize the schemas, schema matching to discover correspondences, and schema integration to generate a unified schema and mapping rules between the integrated schema and source schemas. This resolves conflicts through classification, structural, descriptive and other transformations. Semi-automatic and manual methods can be used for the integration process.