G select * from t1, t2, t3 where t1.f1 = t2.f1 and t1.f1 = t3.f1; (before rewrites) cluster0 Box0:Select cluster3 Box3:BaseTable T3 cluster2 Box2:BaseTable T2 cluster1 Box1:BaseTable T1 boxhead0 Distinct: Preserve 0: Q0.c0 as F1 1: Q0.c1 as F2 2: Q0.c2 as F3 3: Q1.c0 as F1 4: Q1.c1 as F2 5: Q1.c2 as F3 6: Q2.c0 as F1 7: Q2.c1 as F2 8: Q2.c2 as F3 Q0 Q0(F) as T1 Q1 Q1(F) as T2 Q0->Q1 (Q0.c0) = (Q1.c0) Q2 Q2(F) as T3 Q0->Q2 (Q0.c0) = (Q2.c0) boxhead1 Distinct: Preserve 0: c0 as F1 1: c1 as F2 2: c2 as F3 Q0->boxhead1 boxhead2 Distinct: Preserve 0: c0 as F1 1: c1 as F2 2: c2 as F3 Q1->boxhead2 boxhead3 Distinct: Preserve 0: c0 as F1 1: c1 as F2 2: c2 as F3 Q2->boxhead3