Abstract: Structured hierarchical documents containing data, such as XML documents, are input and stored in a structured database such as an XML database. The hierarchical structure of the document is represented as a collection of subtrees in which a subtree can be updated without affecting other subtrees. The relationship between neighboring subtrees is maintained by providing a link node in each subtree that stores a reference to the neighboring subtree. Subtrees can be organized into larger structures to support efficient searching of the structured database.

Abstract: One aspect of the present invention is a system for classifying element nodes in a subtree-structured XML database. The XQE structural-textual classification system is sensitive to both the textual resemblance between document elements as well as the structural resemblance between document elements. The XQE structural-textual classification system might use the XQE parent-child index described in Lindblad II-A for the purpose of forming vectors of “terms” which encode both the structural and the textual content of XML elements. The element vectors are processed by a classifier to create class prototype vectors which can be used to classify elements as they are added to the database.

Abstract: A method for processing queries for a document of elements is provided. The document includes a plurality of subsections where each subsection includes at least a portion of elements in the document. The method comprises: receiving a query for a path of elements in the document of elements; determining a plurality of step queries from the query, each step query including at least a part of the path of elements; for each step query in the plurality of step queries, determining one or more subsections that include elements that correspond to a step query; and determining at least one subsection that includes the path of elements of the query. A result for the query is generated using the at least one subsection.

Abstract: In an XML handling system, point updates to an element of an XML document stored in the database is possible. Updates include addition or deletion of whole documents, addition of a child node to any element node (this includes attribute nodes), the addition of new siblings to any element node, the deletion of any element node, and the replacement of any node by a new node. The database system might include a set of functions that can be invoked to affect an update (i.e., an addition, deletion or modification). Such updates can be submitted as queries, such as instructions within an XQuery query.