If you are using
select() to build a query, upon which you will
build further with
order(), and if some expression that occurs
as an argument to
select() is an exact duplicate of an expression
that occurs in an argument to
order() (possibly as a subexpression), then
consider building that expression just once, and holding it in a
variable that you use and reuse. Using copies of the original is fine
too; what matters is to avoid assembling it from parts multiple times.
If you follow this advice, then quince will use a column alias to avoid repeated evaluations of the expression in the SQL.