1. Collaborative query processing based on reducts

2. Example of a non-local query (DS-term) Database: Flights(airline; departure time; arrival time; departure airport; arrival airport) select * from Flights where airline = "Delta” departure time = "morning" departure airport = "Charlotte" aircraft = "Boeing"

3. (a1*c2)+(d2*a2) (a1*c2)+(a1*b2*a2+d2*a2) (a1*c2)+(a1*b2+d2)*a2 (g1, a2) (g1, a2, a1) (f2, a1*b2+d2) (f2, a1*b2+d2, a2*d1)

4. {d,c,e,g}  {a,b,c,d,f}={c,d} {a,b}, {a,c}, {b,c} {d,c,e,g}

5. = q (c, e, f (b(e), c )) = q (c, e, f (b, c )) = q = q (c, e, f ) = q S1S1 e cb f e c S1S1 S1S1 S2S2 S2S2 S3S3 Tree-resolution for q