OPTIMIZING PROCESSING OF GROUP-BY QUERIES FEATURING MAXIMUM OR MINIMUM EQUALITY CONDITIONS IN A PARELLEL PROCESSING SYSTEM

摘要

A system, method, and computer-readable medium for optimized processing of queries that feature maximum or minimum equality conditions are provided. The disclosed mechanisms provide for a single-scan of the table on which the group-by query is applied. When the table is scanned, each processing module dynamically keeps track of the row(s) having a value of the attribute on which the equality condition is applied that equals or exceeds the maximum attribute value (assuming a maximum equality condition is applied) previously encountered by the processing module. Subsequently, a global aggregation process is then performed to compute the query's result without rescanning the table. Queries featuring a minimum equality condition are similarly processed in accordance with the disclosed embodiments.