- Consider a
vertically distributed
distributed database:
- Problem:
- R is stored at site 1
- S is stored at site 2
- We want to compute the result R ⋈ S at site 3
- There are
- Send a
copy of
R and
S to the result site
and compute the join R ⋈ S there:
- Send a
copy of
R to the site of
S
Compute the join R ⋈ S there (at S)
Send the result to the query site:
- Send a
copy of
S to the site of
R
Compute the join R ⋈ S there (at R)
Send the result to the query site:
- Send a
copy of
R and
S to the result site