Patent ID: 6439783
Filing Date: 2002-08-27
Classification: G06F,Y10S

Abstract:
A method for processing a query that specifies at least one range condition, the method comprising the steps of:(A) creating a Boolean expression that corresponds to the query; (B) evaluating the Boolean expression for a current key value; (C) before evaluating the Boolean expression for a next key value, performing the steps of (C1) determining a limit key based on said Boolean expression and said current key value; (C2) if the Boolean expression evaluates to TRUE for said current key value, then (C2a) fetching a next key value without evaluating the Boolean expression for the next key value; (C2b) repeating step C2a until reaching a next key value that is equal to or greater than the limit key; (C2c) establishing the next key value that is equal to or greater than the limit key as a new current key value and repeating steps (B) through (C) using the new current key value; (C3) if the Boolean expression evaluates to FALSE for said current key value, then (C3a) skipping to a next key value that is equal to or greater than the limit key; and (C3b) establishing the next key value that is equal to or greater than the limit key as a new current key value and repeating steps (B) through (C) using the new current key value.