Union

class Union : PhysicalOperator (source)

Union physical operator.

Union(physicalPlan: PhysicalPlan)

Union physical operator.

val physicalPlan: PhysicalPlan

The physical plan where we have to perform the union on its children.

cardinality	`open val cardinality: Long` Delegate cardinality to the physical plan.
firstChild	`open val firstChild: PhysicalOperator` The first set of data to operate on.
lastChild	`open val lastChild: PhysicalOperator` The last set of data to operate on.

cost	`fun cost(): Long` Cost of the union operation.
evaluate	`fun evaluate(): PathStream` Evaluate the union.