Quest SQL Optimizer for SQL Server v10.0.3
Quest SQL Optimiser validates database code to ensure the best-possible performance by helping you proactively identify potential issues and automate the SQL optimisation process. The SQL Server Query Optimizer is a cost-based optimizer. It analyzes a number of candidate execution plans for a given query, estimates the cost of each of these plans and selects the plan with the lowest cost of the choices considered. Indeed, given that the Query Optimizer cannot consider every possible plan for every query, it actually has to do a cost-based balancing act, considering both the cost of finding potential plans and the costs of plans themselves.