Efficient Query Relaxation for Semistructured Data

Semistructured data, such as XML, allows authors to structure a document in a way which accurately captures the semantics of the data. This, however, poses a substantial barrier to casual and non-expert users who wish to query such data, as it is the data's structure which forms the basis of all XML query languages. Without an accurate understanding of this structure, users are unable to issue meaningful queries. This problem is compounded when one realizes that data adhering to different schema are likely to be contained within the same data warehouse or federated database