XDB-IPG : An Extensible Database Architecture for an Information Grid of Heterogeneous and Distributed Information Resources

This paper describes XDB-IPG, an open and extensible database architecture that supports efficient and flexible integration of heterogeneous and distributed information resources. XDB-IPG provides a novel “schema-less” database approach using a document-centered object-relational XML database mapping. This enables structured, unstructured, and semi-structured information to be integrated without requiring document schemas or translation tables. XDB-IPG utilizes existing international protocol standards of the World Wide Web Consortium Architecture Domain and the Internet Engineering Task Force, primarily HTTP, XML and WebDAV . Through a combination of these international protocols, universal database record identifiers, and physical address data types, XDBIPG enables an unlimited number of desktops and distributed information sources to be linked seamlessly and efficiently into an information grid. XDB-IPG has been used to create a powerful set of novel information management systems for a variety of scientific and engineering applications. Introduction – The Information Grid The Information Power Grid (IPG) is the National Aeronautics and Space Administration’s (NASA) project for providing seamless access to distributed information resources regardless of location [29]. The project addresses three major categories of distributed resources: 1) hardware resources, such as super computers and scientific instruments, 2) software resources, such as teamwork and CAD programs, and 3) data resources, such as data archives and document databases. This paper is concerned with data resources. While much recent work in this area is focused on access to structured data archives, our focus is on integrating structured, semi-structured, and unstructured information. As with many enterprises, information and information processes services at NASA are highly distributed. NASA and its contractors have hundreds of databases with millions