Method and system for executing a query having multiple distinct key columns

摘要

A method and system for executing a query to access data stored in a database, wherein the query includes a plurality of DISTINCT keys, is disclosed. The method and system of the present invention includes providing a first DISTINCT operation on a first DISTINCT key, storing data fetched from the first DISTINCT operation in a master workfile if more than one sort process is needed to execute the query, and utilizing the master workfile to perform subsequent DISTINCT operations for the other DISTINCT keys.