Performance Analysis of Various Query Optimizer Models in Query Optimization

Query Optimization has emerged as the most significant factor in today's database systems to achieve significant performance gains. It plays a vital role in tuning overall performance of the database system. The primary challenge of any database systems is to maintain the information in such a way that it can be accessed efficiently. To determine the efficient way to execute query can be done by Query Optimizer. In this paper we briefly introduce the concept of query optimization and the role of query optimizer in query optimization. This study would help the developer and database administrator to understand about the query optimizer and the technique it uses to select an access path and prepare a Query Execution plan. Modern database applications demand Query Optimizers that are extensible and efficient. Although many research works have been carried out in this field but still there are some shortcomings in each optimizer model developed. In this paper we have discussed about the shortcomings of various optimizer models and we have also proposed a new optimizer model which can meet the growing need of today's database applications.