Index format
Scalar index of SEX:
[F, 2]
[F, 5]
[M, 1]
[M, 3]
[M, 4]
RID-set index of SEX:
[F, {2, 5}]
[M, {1, 3, 4}]
Computed RID-set for expression SEX = ‘M’ AND DEPTNO = 10:
{1, 3, 4} ? {1, 2, 4} ? {1, 4}
RID EMPNO ENAME DEPTNO SEX 1 10 FRED 10 M 2 11 WILMA 10 F 3 12 DINO 30 M 4 13 BARNEY 10 M 5 14 BETTY 20 F