[[breaking_50_aggregations_changes]] === Aggregation changes ==== Significant terms on numeric fields Numeric fields have been refactored to use a different data structure that performs better for range queries. However, since this data structure does not record document frequencies, numeric fields can no longer be used for significant terms aggregations. It is recommended to use <> fields instead, either directly or through a <> if the numeric representation is still needed for sorting, range queries or numeric aggregations like <>.