Save-First Joins

To save only the first match for each element in a collection, use an ee.Join.saveFirst() . The saveFirst() join functions in an equivalent way to the saveAll() join, except for each element in the primary collection, it simply saves the first element from the secondary collection matching the condition specified in the ee.Filter . Unmatched elements in the primary collection are dropped. Unless a sorting property and an order are supplied (as in the saveAll example ), the first element saved might be any of the elements in the list found by saveAll() with the same filter.