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:
Apr. 03, 2001
Filed:
Jul. 31, 1998
Rainer Eberhard, San Jose, CA (US);
Harold H. Hall, Jr., San Jose, CA (US);
Jon A. Youngberg, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
The method of the invention estimates a total processing cost incident to execution of a query statement in respect of a relational database, wherein execution of the query statement results in a further execution of a trigger procedure. The method first estimates the query statement's costs by analyzing components of the query statement to determine a processing time there for in relation to a database table that is the target of the query statement. The method then determines the number of rows that are affected in the database table as a result of execution of the query statement. Next, components of a trigger procedure that is invoked in response to execution of the query statement are analyzed to determine a “base cost” for a single execution of the trigger procedure visa-vis data that is contained in a single row of the database table. The components of the trigger procedure are next analyzed to determine a per row cost for execution of the trigger procedure. The per row cost is determined from an estimate of time required for execution of the trigger procedure for a single row and from an estimate of time required for execution of the trigger procedure for a plurality of rows. Thereafter, the total processing cost of a query statement is calculated by adding the query statement cost to a sum of the either (i) the base cost if only one row is subjected to the query statement or (ii) the per row cost, multiplied by the number of rows affected by the query statement.