Within Toad, you can optimize SQL that has been identified as an issue. This is a self-contained functionality and nothing is required by the respective database vendors (Oracle, MS SQL Server). SQL Optimizer generates semantically equivalent alternatives with unique execution plans for your original SQL statement and then executes the alternatives to test each statement's performance. This will provide you with execution times and runtime statistics that allow you to find the best SQL statement for your database environment.
This is a companion discussion topic for the original entry at https://blog.toadworld.com/2018/07/23/do-you-imbed-your-sql-in-cobol-even-if-you-don-t-toad-can-proactively-find-and-tune-your-sql