The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 30, 1999
Filed:
Dec. 08, 1997
Gautam Bhargava, Cupertino, CA (US);
Piyush Goel, Monte Sereno, CA (US);
Balakrishna R Iyer, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A system and method of determining uniqueness properties of an expression. A root of the expression is first determined, where the root is one of a base relation, a unary operation or a binary operation. Once the root is determined, a first procedure of an augmented unique process is called to determine uniqueness properties of a child of that root. The procedure called is chosen based on the determined root. Where the root is a base relation, a first procedure of a uniqueness process is applied to determine the uniqueness properties of the base relation. Where the root is a unary or binary operation, the called procedure is suspended, a second procedure of the augmented unique process is called to determine the uniqueness properties of the child of the operation, and this process is repeated until a base relation is reached. Once a base relation is reached, the first procedure of the uniqueness process is applied to determine the uniqueness properties of the reached base relation. A next procedure of a uniqueness process is applied to determine the uniqueness properties of a parent operator of the based relation. The procedure applied is chosen based on a type of operation represented by the parent. The process then unwinds to determine the uniqueness properties for each ancestor of the base relation(s).