Patent ID: 6345267
Filing Date: 2002-02-05
Classification: G06F,Y10S

Abstract:
A method of processing a query in a relational database management system that operates in a computer network to retrieve data from computer storage, the method comprising:receiving a query for retrieving data stored in partitioned data tables, the query being associated with an operator and one or more subsequent operators for execution of the query; generating a plurality of interesting partition requirements for the one or more subsequent operators of the query; generating a set of possible partition requirements for the operator of the query; for each possible partition requirement generated for the operator: determining whether the possible partition requirement is the same as one of the interesting partition requirements generated previously for the one or more subsequent operators; and creating an alternative evaluation plan having a partition property that satisfies the possible partition requirement if it is determined that the possible partition requirement is the same as one of the interesting partition requirements generated previously for the one or more subsequent operators.