Relationship to Mathematical Set Theory
The diagrams that follow show the correlation between the Oracle set operator,
the mathematical notation and a Venn diagram representing the relationship.
MINUS operation is analagous to a difference:
INTERSECT named the same as the mathematical operation:
UNION is also named the same as the mathematical operation:
UNION ALL does not have an analagous operation in elementary set theory where there
is no notion of duplicates.
Other mathematical operations can be emulated by combining SQL operations.
For instance, creating a symetric difference can be accomplished by the following combination:
(<query 1> UNION <query 2>)
(<query 1> INTERSECT <query 2>)