Views Raw SQL allows arbitrary SQL expressions to be added to Views, as fields and sorts. This is useful when you want to do something more complicated than Views or Views Calc can do already, e.g. sort by the sum of two fields multiplied by the square root of another field, and you've already built functionality around doing this in Views so it would be a pain to switch to a custom query. IMPORTANT: Views Raw SQL expressions are not safe. They can be used to circumvent data access restrictions with malicious SQL or to break a view with invalid SQL. So be very careful who you grant permission to use this module.