Database query cost model optimizer

US6330552A · kind A · utility

Assignee

• Compaq · US

Inventors

• Christopher M. Farrar · Los Gatos, US
• Harry A. Leslie · Los Altos Hills, US
• Pedro Celis · Redmond, US
• Diana L. Shak · San Jose, US
• Jay Vaishnav · Cupertino, US
• Michael J. Skarpelos · San Jose, US

Key dates

• Filing date: Sep 28, 1998
• Grant date: Dec 11, 2001
• Expiry date: Sep 28, 2018

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S707/99932
• WIPO field: IT methods for management
• WIPO sector: Electrical engineering

Abstract

A method and apparatus is disclosed for accurately estimating the cost of a database query, including the total computer resources used and estimated elapsed time for the production of a first row and last row of an operator involved in the query and/or the total resources used and elapsed time for returning the overall response to a database query. The method and apparatus accurately accounts for resources used and elapsed time associated with blocking operators, such as sorts and hash joins, which cannot produce a first row until they have completed their operations.