From Structured Documents to Novel Query Facilities

Vassilis Christophides, Serge Abiteboul, Sophie Cluet, Michel Scholl

Abstract: Structured documents (e.g., SGML) can benefit a lot from database support and more specifically from object-oriented database (OODB) management systems. This paper describes a natural mapping from SGML documents into OODB's and a formal extension of two OODB query languages (one SQL-like and the other calculus) in order to deal with SGML document retrieval.Although motivated by structured documents, the extensions of query languages that we present are general and useful for a variety of other OODB applications. A key element is the introduction of paths as first class citizens. The new features allow to query data (and to some extent schema) without exact knowledge of the schema in a simple and homogeneous fashion.