Abstract.
XML is rapidly emerging as a standard for exchanging business data on the World Wide Web. For the foreseeable future, however, most business data will continue to be stored in relational database systems. Consequently, if XML is to fulfill its potential, some mechanism is needed to publish relational data as XML documents. Towards that goal, one of the major challenges is finding a way to efficiently structure and tag data from one or more tables as a hierarchical XML document. Different alternatives are possible depending on when this processing takes place and how much of it is done inside the relational engine. In this paper, we characterize and study the performance of these alternatives. Among other things, we explore the use of new scalar and aggregate functions in SQL for constructing complex XML documents directly in the relational engine. We also explore different execution plans for generating the content of an XML document. The results of an experimental study show that constructing XML documents inside the relational engine can have a significant performance benefit. Our results also show the superiority of having the relational engine use what we call an “outer union plan” to generate the content of an XML document.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 15 October 2000 / Accepted: 15 April 2001 Published online: 28 June 2001
Rights and permissions
About this article
Cite this article
Shanmugasundaram, J., Shekita, E., Barr, R. et al. Efficiently publishing relational data as XML documents. The VLDB Journal 10, 133–154 (2001). https://doi.org/10.1007/s007780100052
Issue Date:
DOI: https://doi.org/10.1007/s007780100052