The default rules used by the parser for parsing names of built-in-function can be changed by enabling IGNORE_SPACE SQL mode. When we enable this mode, the parser relaxes the requirement that there be no whitespace between the function name and the following parenthesis. For example, after enabling IGNORE_SPACE SQL mode both of the following function calls are legal −
Select SUM(Salary) from employee; Select SUM (Salary) from employee;
But, in this case, the parser treats the function name as reserved words. It means that a space following the names no longer represents as an identifier.