THE XML REVOLUTION - TECHNOLOGIES FOR THE FUTURE WEB

Queries on XML documents

The database community has long been looking for a richer data model:

but no consensus has emerged yet.

XML documents generalize relational data in a very straightforward manner:

Here, we see:

relations (tables)

tuples (records)

attributes (entries)

A relation is a tree of height two with:

In contrast, an XML document is an arbitrary tree.

How should query languages like SQL be similarly generalized?