Patents by Inventor Grace Au

Grace Au has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Determining materialized view coverage
    Patent number: 6865569
    Abstract: A method and apparatus determines (1) if a materialized view can be used to respond to a query for data stored in one or more base tables of a database system; and/or (2) if the materialized view needs to be updated in response to an update query. A query expression tree represents the query, and a materialized view expression tree represents the materialized view. The components of the query expression tree are compared with components of the materialized view expression tree to determine if the materialized view covers the query that is, the tuples in the result of the query expression are a subset of the tuples in the result of the materialized view expression.
    Type: Grant
    Filed: August 22, 2001
    Date of Patent: March 8, 2005
    Assignee: NCR Corporation
    Inventors: Hong Gui, Curt J. Ellmann, Grace Au, Ahmad S. Ghazal