| Operator | Index type | Memory buffer requirement | # Disk I/O operations |
|---|---|---|---|
| σA=c(R) | Clustering index on R | ≥ 1 | B(R) / V(R,A) |
| σA=c(R) | Non-Clustering index on R | ≥ 1 | T(R) / V(R,A) |
| σA=c(R) | Key attribute | ≥ 1 | 1 |
| R ⋈index S | Clustering index on S | ≥ 2 |
B(R) +
T(R) × B(S)/V(S,Y)
(R clustered)
T(R) + T(R) × B(S)/V(S,Y) (R unclustered) |
| R ⋈index S | Non-Clustering index on S | ≥ 2 |
B(R) +
T(R) × T(S)/V(S,Y)
(R clustered)
T(R) + T(R) × T(S)/V(S,Y) (R unclustered) |
| R ⋈zigzag S |
Clustering index
on R and S |
M−1 ≥ min{
B(R)/V(R,A) ,
B(S)/V(S,A)} |
B(R) + B(S) |
| R ⋈zigzag S |
Non-Clustering index
on R and S |
M−1 ≥ min{
B(R)/V(R,A) ,
B(S)/V(S,A)} |
T(R) + T(S) |
| R ⋈zigzag S |
R unsorted
Clustering index on S |
M ≥ sqrt(B(R)) + ??? | 3B(R) + B(S) |