SAG-DM-03 Document Nodes

In most database systems, documents are likely to have properties extraneous
to the actual XML content of the document, and these properties are often
useful for retrieval. Examples of such properties include document names,
URIs, dates of creation and modification, ownership, security levels,
document size, associated schema, document version, and so on. They may also
include user-allocated properties, for example the approval status of the
document in some publication workflow.

Many XML database systems are likely to want to offer other interfaces in
addition to XQuery. A popular interface for content management systems is
the WebDAV interface. WebDAV allows a document to have an arbitrary set of
properties, including properties under the control of the system and
properties under the control of the user.

Document nodes constructed by a query may also have properties, for example
the MIME media type, the serialization parameters, and the intended
destination of the document when serialized.

We think it would be useful to extend the data model to allow a document
node to have such a set of properties. It should be possible to query these
properties, and to set them when constructing a document node. It should be
understood that the properties are accessible to applications but that they
are not serialized as part of the document content.

A possible (though controversial) design that would meet this requirement is
to allow a document node to have attributes.

Michael Kay
Software AG

Received on Tuesday, 10 June 2003 11:49:46 UTC