Managing the operator ordering problem in parallel databases

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 signiicant 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%) without loosing quality. Finally we demonstrate that existing commercial parallel query optimizers need little extension modiications in order to handle LBTs.