Parameters, also called variables, can be embedded in a SQL statement without pre-defining the data type and value. All variable names are highlighted in red (by default) after the formatting. Variables with or without a "@" sign are recognized. When you optimize the SQL statement or retrieve the query plan, run time, the run result for a SQL statement that uses a parameter, you are prompted to enter the variables using the Parameters window.
Note: You can retrieve the query plan for a SQL statement that has a variable without the need to enter the data type or value by executing the Show Default Plan function from the SQL menu.