As pointed out by one of the students, the scoring functions need to be defined by linear arithmetic expressions to guarantee monotonicity.
So they are of the form
c1* A1+....cn*An
where c1,...cn are positive integer coefficients.
A*B where A and B are attributes is not part of the query language.
--jc
Can we assume there will not be any queries as following?
ReplyDeleteA1 * A2 + c2 * A3
A1, A2 and A3 are the attributes of the relation
Right, an attribute can only be multiplied by a positive integer constant.
ReplyDelete--jc