Managing the operator ordering problem parallel databases

摘要

This paper focuses on parallel query optimization. We consider the operator problem and introduce a new class of execution strategies called Linear-oriented Bushy Trees (LBT). Compared to the related approach of the General Bushy Trees (GBT) a significant complexity reduction of the operator ordering problem can be derived theoretically and demonstrated experimentally (e.g. compared with GBTs, LBTs authorize optimization time improvement that can reach up to 49/100) without losing quality. Finally we demonstrate that existing commercial parallel query optimizers need little extension modifications in order to handle LBTs.