Suppose you are a Database developer. You have created lot of tables, views, SP etc. for your development. You have also put the required indexes on the tables for query optimizing etc. Now your database is deployed to production environment and you found that everything is running properly.
Now after long period of time of performance the data volume will be increased and you found that your database performance has been degraded as compared to the previous while there was a small volume of data. Now once again going through the database design, putting the new indexes is not an easy task to do, it may take huge effort and at last it may not be fruitful at all.
SQL-SERVER has SQL Server-Profiler tool to help us optimize our database.