Parallel processing of "GroupBy-Before-Join" queries in cluster architecture

SQL queries in the real world are replete with group by and join operations. This type of queries is often known as "GroupBy-Join" queries. In some GroupBy-Join queries, it is desirable to perform group-by, before join in order to achieve better performance. This subset of GroupBy-Join queries is called "GroupBy-Before-Join" queries. In this paper, we present a study. on parallelization of GroupBy-Before-Join queries, particularly. by, exploiting cluster architectures. Front our study,, we have learned that in parallel query optimization. processing group-by, as early, as possible is not always desirable. In many occasions, performing data distribution first before group-by offers performance advantages. In this study,, we also describe our cluster-based scheme.