Design and Implementation of OSCAR Query Optimizer
Chun Chen · Jisuanji yingyong yanjiu · 2005
Query optimization is an important element of database manager system. First,this paper introdues importance of query optimization in database manager system and describes the common processing steps of OSCAR query optimization. Se￣condly,the paper mainly discuss the design and implementation of OSCAR query optimization.In query optimization module,the technique of query preprocessing and pulling subquery up is introduced,then the access path selection and the account method of const evaluation are discussed in detail.Finally,an analysis to experimental is given.It indicates that the query efficiency of optimized OSCR increases obviously.