The "any other expression" or "arbitrary expressions" must still yield a value associated with each row to be sorted, if the sort is to have any effect. A constant value is not going to do anything useful. If you can express your table with sorting values as an appended column, (with a join of some kind), then you can sort on the appended column and retain only the original table columns in the result set. I suspect that you are imagining that the original table has some order, and that you can match that up with some other table also having some order then sort both together. It would be best to abandon thinking like that. Tables have no order beyond what can be imposed on result sets via ORDER BY.