index concept

PK IX_Last

ID LastName ID LastName

1 L 1 L

2 L 2 L

3 T 5 L

4 T 7 L

5 L 9 L

6 T 10 L

7 L 3 T

8 T 4 T

9 L 6 T

10 L 8 T

where LastName = “L" will use IX_Last