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:
Jun. 15, 2010
Filed:
Sep. 08, 2006
Zhen Hua Liu, San Mateo, CA (US);
Muralidhar Krishnaprasad, Fremont, CA (US);
Hui Joe Chang, Fremont, CA (US);
Anand Manikutty, Foster City, CA (US);
James W. Warner, Lake Oswego, OR (US);
Vikas Arora, San Francisco, CA (US);
Susan Kotsovolos, San Carlos, CA (US);
Zhen Hua Liu, San Mateo, CA (US);
Muralidhar Krishnaprasad, Fremont, CA (US);
Hui Joe Chang, Fremont, CA (US);
Anand Manikutty, Foster City, CA (US);
James W. Warner, Lake Oswego, OR (US);
Vikas Arora, San Francisco, CA (US);
Susan Kotsovolos, San Carlos, CA (US);
Oracle International Corporation, Redwood Shores, CA (US);
Abstract
A method for optimizing queries is described. A query, which includes a first expression for determining whether each of a set of values evaluates to NULL or NOT NULL, is received. At compile-time, a first representation of the query is generated, where the first representation indicates that the query is to be performed based on the first expression. Based on the first expression, a second expression is determined. The second expression is such that the first expression would evaluate to any NOT NULL value if and only if the second expression would evaluate to any NOT NULL value. The second expression, when evaluated, is much more computationally efficient compared with the evaluation of the first expression. Based on the first representation, a second representation of the query is generated, where the second representation indicates that the query is to be performed based on the second expression. Thereafter, the query is executed based on the second representation.