_field_names field
edit_field_names
field
editThe _field_names
field used to index the names of every field in a document that
contains any value other than null
. This field was used by the
exists
query to find documents that
either have or don’t have any non-null
value for a particular field.
Now the _field_names
field only indexes the names of fields that have
doc_values
and norms
disabled. For fields which have either doc_values
or norm
enabled the exists
query will still
be available but will not use the _field_names
field.
Disabling _field_names
editDisabling _field_names
is no longer possible. It is now enabled by default
because it no longer carries the index overhead it once did.
Support for disabling _field_names
has been removed. Using it on new
indices will throw an error. Using it in pre-8.0 indices is still allowed but
issues a deprecation warning.