Join Order Optimization in Multi-Relation SQL Query
Hong Mei · Journal of Hangzhou Dianzi University · 2006
The way of relational database optimizer to determine execution plans of SQL query is very complicated.This paper briefly introduces how each stag in developing management information system is optimized;organization of optimizer and its optimization strategy are also described including how the execution plans of SQL query are available.There are several executing ways or execution plans for one SQL statement,which can get the same result,but the efficiency is far more different.Limited to pages number,only expression of SQL query and algorithm for generating the execution plans are presented.Optimization includes join algorithm optimization,join order optimiza-tion,semantic optimization,index optimization and so on.But in this paper,we emphasis on join order optimization and a case about multi-relation join order optimization based on Oracle is given.