OLAP Query Evaluation in a Database Cluster: A Performance Study on Intra-Query Parallelism

摘要: While cluster computing is well established, it not clear how to coordinate clusters consisting of many database components in order process high workloads. In this paper, we focus on Online Analytical Processing (OLAP) queries, i.e., relatively complex queries whose evaluation tends be time-consuming, and report some observations preliminary results our PowerDB project context. We investigate nodes should used evaluate an OLAP query parallel. Moreover, provide a classification which decide, whether parallelized. run extensive experiments these classes quantitative terms. Our are important step towards two-phase optimizer. the first phase, coordination infrastructure decomposes into subqueries ships them appropriate nodes. second each node optimizes evaluates its subquery locally.