Patents by Inventor Grace Kwan-On Au

Grace Kwan-On 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).

  • Patent number: 8140521
    Abstract: A method, computer program, and database system are disclosed for processing a database query that includes one or more expressions. The method includes resolving columns in one or more of the expressions. Expression optimization is performed on one or more of the expressions. Afterward, further query optimization is performed.
    Type: Grant
    Filed: March 15, 2004
    Date of Patent: March 20, 2012
    Assignee: Teradata US, Inc.
    Inventors: Stephen Fife Sheldon, Arthur Vargas Lopes, Grace Kwan-On Au, Ahmad Said Ghazal
  • Patent number: 8024286
    Abstract: Techniques for independent column detection in selectivity estimations are provided. Values for database statistics are sampled and two independent tests are performed against the values for a first column and a second column. When each test determines that the first and second columns are independent, the first and second columns are said to be independent columns for selectivity estimation.
    Type: Grant
    Filed: January 8, 2009
    Date of Patent: September 20, 2011
    Assignee: Teradata US, Inc.
    Inventors: Grace Kwan-On Au, Rama Krishna Korlapati, Haiyan Chen
  • Publication number: 20100174702
    Abstract: Techniques for independent column detection in selectivity estimations are provided. Values for database statistics are sampled and two independent tests are performed against the values for a first column and a second column. When each test determines that the first and second columns are independent, the first and second columns are said to be independent columns for selectivity estimation.
    Type: Application
    Filed: January 8, 2009
    Publication date: July 8, 2010
    Inventors: Grace Kwan-On Au, Rama Krishna Korlapati, Haiyan Chen
  • Patent number: 7640229
    Abstract: A method for processing a trigger are described. The trigger is associated with a subject table in a relational database and defines a triggering statement and one or more triggered actions. The method includes determining that a triggering statement of a trigger will execute on a subject table row of a subject table and requesting a transition table in response to determining that the triggering statement will execute. The transition table includes a transition table row. The transition table row includes a first value associated with the subject table row and a second value associated with the subject table row. The method further includes reading the transition table row from the transition table and identifying a processing unit to receive the transition table row and a triggered action of the trigger. The method also includes transmitting the transition table row and the triggered action to the identified processing unit to be processed.
    Type: Grant
    Filed: December 15, 2003
    Date of Patent: December 29, 2009
    Assignee: Teradata US, Inc.
    Inventors: Frederick S. Kaufmann, Grace Kwan-On Au, Venkata Ramakrishna Tirunagari
  • Patent number: 7260563
    Abstract: A method, database system, and computer program are disclosed for optimized costing. The method includes identifying a join that identifies a first table and a second table. The method further includes determining an optimized cost of reading the first table. If the number of unique first table values is greater than the number of unique second table values, the number of instances where a unique first table value matches a unique second table value is returned. Otherwise, the number of unique first table values is returned. The method further includes determining an optimized cost of reading the second table. The optimized cost of reading the second table includes the number of unique second table values. The method also includes summing the optimized cost of reading the first table and the optimized cost of reading the second table.
    Type: Grant
    Filed: October 8, 2003
    Date of Patent: August 21, 2007
    Assignee: NCR Corp.
    Inventors: Bibhu Ranjan Priyadarshi, Grace Kwan-On Au, Kuorong Chiang
  • Patent number: 7171397
    Abstract: A method and computer program are disclosed for measuring the parallelism of an execution step. The method includes determining whether the step operates on rows whose primary index is specified. If the primary index is specified, the parallelism is measured as single. If the primary index is not specified, the method determines whether the step uses an output from a previous step. If an output is used, the number of rows in the output is compared to a specified number. If the number of rows is greater than the specified number, the parallelism is measured as total. In one implementation, the geography of the output is determined and the previous step is compared to specified types such that if the primary index is not specified, the number is rows is not greater than a specified number, the geography does not write output rows to all parallel units, and the previous step is of a specified type, then the parallelism is measured as partial.
    Type: Grant
    Filed: August 21, 2002
    Date of Patent: January 30, 2007
    Assignee: NCR Corp.
    Inventors: Grace Kwan-On Au, May Wat Pederson, Sang-Luen Helen Fan
  • Patent number: 6732096
    Abstract: A method and computer system for optimizing queries to a database are disclosed. The query specifies one or more data-to-be-aggregated columns (DAC), one or more explicit aggregation keys (EAK) and one or more join conditions. The query involves table T1. T1includes the one or more data-to-be-aggregated columns and an aggregation key. All join conditions that involve T1 join the aggregation key of T1 to the unique primary index of another table that is involved in the query. T1 is joined to a table T2 in accordance with a join condition of the aggregate join query. The joining process includes sorting T1 on a sort key that is the aggregation key. Aggregation processing is combined into the step of sorting if T1 is a significant table. Aggregation processing is also combined into the step of sorting if T2 is a significant table and the first join condition is between the aggregation key of T1 and the unique primary index of T2.
    Type: Grant
    Filed: July 30, 2001
    Date of Patent: May 4, 2004
    Assignee: NCR Corporation
    Inventor: Grace Kwan-On Au
  • Patent number: 6643636
    Abstract: A method, database system and computer program are disclosed for optimizing a SQL query, in which the SQL query includes a WHERE clause and a FROM clause. An evaluation is done to determine whether a non-covering join index partially but not completely covers the query. If it does, the join index is added to the FROM clause of the query without removing the partially covered base tables and the WHERE clause of the query is modified by: (1) mapping a query condition to the join index for its partially covered base tables; and (2) adding a join back condition from the join index to a base table from which the join index was formed.
    Type: Grant
    Filed: June 5, 2001
    Date of Patent: November 4, 2003
    Assignee: NCR Corporation
    Inventors: Grace Kwan-On Au, Ahmad Said Ghazal, Paul Laurence Sinclair
  • Patent number: 6618720
    Abstract: The retrieval of data from a database in a computerized database management system is optimized through the use of a plurality of join indexed. The join indexes are defined for a table stored in the database. The join indexes are updated to reflect any updated records stored in the table, wherein one or more common joins are identified among the join indexes, each of the common joins are materialized only once in a common spool file, and the common spool file is used to materialize one or more rows for updating the join indexes.
    Type: Grant
    Filed: June 15, 2000
    Date of Patent: September 9, 2003
    Assignee: NCR Corporation
    Inventors: Grace Kwan On Au, Chi Kim Hoang
  • Patent number: 6505189
    Abstract: The retrieval of data from a database in a computerized database management system is optimized through the use of an aggregate join index. The aggregate join index combines one or more commonly-used columns of the base tables with the results from one or more aggregation expressions pre-computed from one or more columns of the tables.
    Type: Grant
    Filed: June 15, 2000
    Date of Patent: January 7, 2003
    Assignee: NCR Corporation
    Inventors: Grace Kwan On Au, Chi Kim Hoang