Revamping SQL queries for cost based optimization

There exists manifold ways of scripting a query to reach an equivalent business logic. Nonetheless, a query might satiate the intended business logic; it might be insidious in the perspective of an execution plan. Optimal execution plan is ensured when the query goes on minimal time and resources. In the case of a draw over optimal execution plans the one with lowest predicted execution time must be favored. As such, this paper proposes various re-writing techniques for ensuring Cost based optimization of queries. The exploratory analysis presented in this paper would serve as a tuning/rewriting tool to overhaul query practice and processing(s) on production databases. Pragmatic results of our methodologies and explorations strongly advocate that operational costs and query performance and operational costs are enhanced.