How to decrease the size of nvd files?

I am trying to decrease the size of my index.
I saw that the nvd files are used for norms and boost factors.
I have no need for ranking in my cluster, is it possible to change index/cluster definitions to reduce or cancel those files?
I already tried using "norms:" {enabled: "false"} but it had only a small impact on the index size…
If you have any other ideas for decreasing the index volume please let me know.

You could try setting the fields to not indexed.

I still need to use the search utilities but I don't need the ranking .
I already tried the following:

  1. Mapping definitions:
    Doc_values : false (if possible)
    include_in_all: false (if possible)
    not_analyzed: false (if possible)
  2. Optimize (didn't help for large indexes only small indexes)
  3. Compress with best compression (deflate)