A trait that should be mixed into query operators where an single instance might appear multiple
times in a logical query plan. It is invalid to have multiple copies of the same attribute
produced by distinct operators in a query tree as this breaks the guarantee that expression
ids, which are used to differentiate attributes, are unique.
Before analysis, all operators that include this trait will be asked to produce a new version
of itself with globally unique expression ids.
A trait that should be mixed into query operators where an single instance might appear multiple times in a logical query plan. It is invalid to have multiple copies of the same attribute produced by distinct operators in a query tree as this breaks the guarantee that expression ids, which are used to differentiate attributes, are unique.
Before analysis, all operators that include this trait will be asked to produce a new version of itself with globally unique expression ids.