Introdiuction to Query Optimizer

     In Practical case most of the DBE's can not find the query that optimized execution process of the query.
          The question that arises when database Engine executes a query is how the data that is necessary for the query can be accessed and process most efficient manner. The component of the Database Engine that responsible for such  thing called query optimizer.
           The task of the query optimizer is to consider variety of possible execution strategies for querying the data relation to given query and select most efficient strategy for executing and it is called execution plan. The optimizer make its decisions using considerations such as How big the tables are that involved with the query and what indices exist, What Boolean operations are use in WHERE closes like statistics. There are different tools that can edit query optimize in SQL Server. We will discuss that in later posts.