AppT op of min (k, |A (x) | ) answers, such that w(a) ≤ θ · w(a ) holds for all a ∈ AppT op and
a ∈ A (x) \ AppT op [ Fagin et al. , 2001 ]. There are two advantages of enumeration algorithms with polynomial delay to find top- k answers:
first, the total running time is linear
in k[r]