A Query Language for XML


One important application of XML is the interchange of electronic data (EDI) between multiple data sources on the Web. We expect that in the near future, organizations will export data in XML to facilitate cooperation and exchange with other organizations. For example, businesses may publish detailed technical data about their products and services for consumption by potential customers, or business partners may exchange internal operational data on secure channels. New opportunities will arise for third-party information brokers to integrate, clean, and aggregate public data from multiple sources, or to clean and transform data to facilitate exchange among partners. For such a vision to be realized, the right tools for managing XML data must exist. Such tools must support: Considerable experience for building such tools exists in the context of relational and object-oriented data. At their core, these tools use a standard query language, either relational (SQL) or object-oriented (OQL). We argue that a standard query language for XML must also exist. Given the historical influences of SQL and OQL, our recent research on semistructured data, and XML's own characterisitics, we argue that the language must have the following properties: