Patent ID: 6212514
Filing Date: 2001-04-03
Classification: G06F,Y10S

Abstract:
A method for estimating a total processing cost for executing a query statement with respect to a relational database, wherein execution of said query statement results in a further execution of a trigger procedure, said method comprising the steps of:estimating a query cost of said query statement in relation to a database table that is a target of said query statement;determining a number of rows that are affected in said database table as a result of execution of said query statement;analyzing components of a trigger procedure that is invoked in response to execution of said query statement to determine a base cost for a single execution of said trigger procedure in relation to data contained in a single row of said database table;further analyzing components of said trigger procedure to determine a per row cost for execution of said trigger procedure; andcalculating said total processing cost by adding said query cost to a sum of said base cost, plus said per row cost multiplied by the number of rows affected by said query statement, as determined by said determining step.