- new `rank_feature`/`script_score` queries
- new `index_phrases`/`index_prefixes` options
- disabling `_field_names` doesn't help anymore
- adaptive replica selection is on by default
Some features have been deprecated since `6.0` like the `_parent` field or the
ability to have multiple types per index. This allows to remove quite some
code, which in-turn will hopefully make it easier to proceed with the removal
of types.
James Rodewig
Adrien Grand
Sue Gallagher
Clinton Gormley