Architectures for querying contents of Web servers

A new architecture for a queryable Web server is presented. This architecture is of a three-tier type and consists in using an interpreter of a query language as a gateway for the server, and an XML wrapper as a gateway for data repositories. The query language is used not only to read the server's data, but also to define, manipulate, and control both data and their corresponding meta-data (data descriptions). The XML wrapper allows storing both data and meta-data in a repository of any type, not only a flat file system or a back-end database. Basic requirements for the query language and the wrapper are presented and discussed in comparison to current approaches.