Parallel "GroupBy-Before-Join" Query Processing for High Performance Parallel/Distributed Database Systems

GroupBy-Join queries in SQL are queries involving the group by clause joining several tables. In this paper, we describe three parallelization techniques for GroupBby-Join queries, particularly the queries where the group-by clause can be performed before the join operation. We subsequently call this query "GroupBy-Before-Join" queries. Performance evaluation of the three parallel processing methods is also carried out