That is the whole index that is causing it, as docvalue_fields is a map of all the fields in your index. I assume your data is very sparse and you have way too many fields.
You can read more about them in the Elasticsearch documentation: Retrieve selected fields from a search | Elasticsearch Guide [8.7] | Elastic
Increasing that number will have a large effect on performance, both for Kibana and Elasticsearch. I would suggest looking at your index and your data modelling to avoid having too many fields.
Apache, Apache Lucene, Apache Hadoop, Hadoop, HDFS and the yellow elephant
logo are trademarks of the
Apache Software Foundation
in the United States and/or other countries.