1
Ahmad Ghazal, Curtis Ellmann: Determining the satisfiability and transitive closure of conditions in a query. NCR Corporation, Baker Botts, January 24, 2006: US06990484 (9 worldwide citation)

A method and computer system for improving the efficiency of execution of a database query that includes conditions is disclosed. Satisfiability of the conditions is analyzed before executing the query. If the conditions are satisfiable, the transitive closure of the conditions is analyzed and the c ...


2
Donald Reichart, Pradeep Sathyanarayan, Ahmad Ghazal: Method and system for rewriting a database query. Teradata US, Steve McDonald, February 2, 2010: US07657567 (1 worldwide citation)

The invention relates to a method and database system for rewriting a SQL query having at least one null sensitive expression (NSE) in a select list of the query, the query comprising at least one outer join command to be performed on at least two tables and involving a view or a Derived Table (DT). ...


3
Ahmad Ghazal: Optimizing nested database queries that include windowing operations. Teradata US, Ramin Mahboubian, January 24, 2017: US09552392

A nested database query can be optimized by effectively representing a filtering function or operation (e.g., SQL filtering operation) of its outer sub-query by a qualification or qualify operation (e.g., SQL qualification operation) associated with at least one windowing function of at least one of ...


4
Ahmad Ghazal: Determining satisfiability and transitive closure of a where clause. James M Stover, Teradata Corporation, July 3, 2008: US20080162445-A1

In general, the invention features a computer-implemented method for improving the efficiency of execution of a database query including a WHERE clause. The method includes analyzing the satisfiability of the conditions associated with the WHERE clause before executing the query. Furthermore, the me ...


5
Donald Reichart, Pradeep Sathyanarayan, Ahmad Ghazal: Method and system for rewriting a database query. James M Stover, Teradata Corporation, June 26, 2008: US20080154841-A1

The invention relates to a method and database system for rewriting a SQL query having at least one null sensitive expression (NSE) in a select list of the query, the query comprising at least one outer join command to be performed on at least two tables and involving a view or a Derived Table (DT). ...


6
William McKenna, Ahmad Ghazal: Method and system for improving sql database query performance. James M Stover, Teradata Corporation, June 19, 2008: US20080147596-A1

Methods and systems for rewriting database queries, and in particular databases using Structured Query Language (SQL). The method comprises the steps of reviewing a SQL query statement having a SELECT list to determine if a view definition of the query has one or more unreferenced view columns; and ...