Existence operator

This operator tests an existence predicate and can be used with the type EXISTS (semi join) and NOT_EXISTS (anti semi join). The predicates can be evaluated against the element from the first input and the second input.
Semi join: All elements in the first input for which there are elements in the second input that fulfills the predicate are sent.
Semi anti join: All elements in the first input for which there is no element in the second input that fulfills the predicate are sent.

Parameter

• Predicate: The predicate

• Type: Either EXISTS or NOT_EXISTS


Example

output = EXISTENCE({
                    type='EXISTS', 
                    predicate='auction = auction_id'
                   }, left, right)

output = EXISTENCE({
                    type='NOT_EXISTS', 
                    predicate='auction = auction_id'
                   }, left, right)