The Research And Design Of Full Reducer Algorithm Based On Data Compression In Distributed Query Optimization

Distributed query optimization research is under way in universities,research laboratories and similar establishments. It is a very active research area in distributed database systems. There is difference between centralized database and distributed database,which distributed database needs data transportation. So most research of distributed query optimization aim at reducing communication cost. The distributed query optimization problem is the key point in distributed database systems,and it is an NP hard one. By keeping the above facts,I delved deeply in distributed query optimization algorithms,made some notable achievement.The paper focuses primarily on distributed query optimization. In distributed query optimization,this paper aims at how to reduce communication cost,adopting semi-join program. As for traditional SDD-1 algorithm,this paper tries to improve it in the following aspects:(1) During data transportation,this paper adopts data compression technology. Another encoding model -TAG model- is put forward here which is different from existing models. And TAG algorithm is given here to implement TAG model;(2) Based on above work,this paper also provides FRD algorithm by using TAG algorithm. FRD algorithm uses semi-join program,in order to find a full reducer.