I recently do some working with tune on disk usage following the doc: https://www.elastic.co/guide/en/elasticsearch/reference/6.4/tune-for-disk-usage.html.
Then I tried store those values in those three settings:
- with _source=true (doc_values=false, store = false)
- with doc_values=true (_source=false, store = false)
- with store=true(_source=false, doc_values=false)
With my Testing, I found there's nearly no difference on disk usage with those three settings when the doc values are difference (disk usage got following the doc: https://www.elastic.co/guide/en/elasticsearch/reference/6.4/indices-stats.html)
But in my opinion, doc_values which stores in column-oriented fashion should use less disk spaces. So are there anything wrong?