Cooperative Query Answering for Semistructured Data

Barg, M. and Wong, R.K.

Semistructured data, in particular XML, has emerged as one of the primary means for information exchange and content management. The power of XML allows authors to structure a document in a way which precisely 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 structure of the data which forms the basis of all XML query languages. Without an accurate understanding of how the data is structured, users are unable to issue meaningful queries. This problem is compounded when one realises that data adhering to different schema are likely to be contained within the same data warehouse or federated database. This paper proposes a method which enables users to meaningfully query semistructured data with no prior knowledge of its structure. We describe a mechanism for returning approximate answers to a database query when the structure of the underlying data is unknown. Our mechanism also returns useful results to the user if a specific value in the query cannot be matched. We discuss a number of novel query processing and optimisation techniques which enable us to perform our cooperative query answering in an efficient and scalable manner.

Cite as: Barg, M. and Wong, R.K. (2003). Cooperative Query Answering for Semistructured Data. In Proc. Fourteenth Australasian Database Conference (ADC2003), Adelaide, Australia. CRPIT, 17. Schewe, K.-D. and Zhou, X., Eds. ACS. 209-215.

(from crpit.com) (local if available)