- Two fields <K(i),P(i)>
- Ordering key field and pointer to block
- Second example, indexing candidate key Surname
- K(1)="Barnes",P(1) -> block 1
- Barnes record is first/anchor entry in block 1
- K(2)="Smith",P(2) -> block 6
- K(3)="Zeta",P(3) -> block 8
- Dense (K(i) for every record), or Sparse
- Enforce key constraint
In Focus
2.2.10. Primary Index file (as pairs list)