Patent ID: 7739219
Filing Date: 2010-06-15
Classification: G06F

Abstract:
1. A method for processing queries comprising the computer- implemented steps of: receiving a query that specifies a target set of data, wherein the query includes a count operator that is to be performed over a first set of values; wherein the count operator specifies a first expression which, when evaluated over the target set of data, would generate the first set of values; generating a first representation of the query, wherein the first representation indicates that the count operator is to be performed based on the first expression; determining a second expression based at least on the first expression, wherein 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; wherein determining the second expression includes: based on the first representation, generating a second representation of the query which indicates that the count operator is to be performed based on the second expression; wherein the steps of the method are performed by one or more computer systems.