A(a1 (primary key), a2, a3)
Statistics: T(A) = 100, V(A,a2) = 30, V(A,a3) = 20
Columns having an index: a1, a2

B(b1 (primary key), b2, b3)
Statistics: T(B) = 50, V(B,b2) = 100, V(B,b3) = 50
Columns having an index: b1, b3

C(c1 (primary key), c2, c3)
Statistics: T(C) = 100, V(C,c2) = 10, V(C,c3) = 50, V(C,c3 = 5) = 10
Columns having an index: c3

Query:
Select c3 from A, B, C where A.a1 = B.b2 and B.b2 = C.c2 and C.c1 > 10 and C.c3 = 5