Relational Algebra: the Mathematical Set operations
- Set operations
- I can be very brief with
this topic
because you have had these
operations in
High School Mathematics classes
- You should all know what set union is:
- Suppose A = {i, j, k} and B = {k, x, y}
- Then the union of A and B is {i, j, k, x, y}
- Note that tuples in sets A and B must have the same
FORMAT (same number and type of attributes)
to be used in the union operation.
- You should also have learned what
set intersection is:
- Suppose A = {i, j, k} and B = {k, x, y}
- Then the intersection of A and B is {k}
- Note that tuples in sets A and B must have the same
FORMAT (same number and type of attributes)
to be used in the intersection operation.
- You should also have learned what
set difference is:
- Suppose A = {i, j, k} and B = {k, x, y}
- Then the difference of A and B is {i, j}
- Note that tuples in sets A and B must have the same
FORMAT (same number and type of attributes)
to be used in the set difference operation.
- I have already discussed the
cartesian product:
click here