Docs.deleted value not changing

I have a non-prod cluster that I use to run tests. I took a snapshot of my prod cluster data and restored it into this non-prod cluster which created the two indices that I have in production. However when I GET _cat/indices?v on this test cluster the docs.deleted value (which is non-zero for both indices) for those two indices hasn't changed ever. Any idea why this is happening? These indices have not been used since they were created, so could this lack of activity on the indices be the reason?

Are you deleting docs?

No I'm not deleting docs. I'm not even using the indices yet, I just set them up two days ago and noticed today that the docs.deleted value has not changed for either index.

Then I wouldn't worry too much.

Deletes can happen due to updates as well. But if you're not doing either it's not a concern.

Thanks for your reply. I'm trying to understand how docs.deleted works. Is that value staying the same because the indices are idle(i.e I'm not using them yet)? According to this, There is nothing you need to do to enable merging. It happens automatically while you are indexing and searching. So since my indices are idle, automatic merges are not happening?

It'll change when documents are updated or deleted. You can still read from or write to an index and that number will not change. It doesn't mean the index is idle.

By "idle" I meant that I'm not using those indices yet. I'm still writing the client code that will interact with them.

You can still read from or write to an index and that number will not change.

I see. I was expecting docs.deleted to decrement. I thought merging would've been happening since the creation of the indices.

Can you share the output from the cat call?

pri rep status docs.deleted health docs.count store.size
  5   1 open        2156999 green     7573689     53.9gb         26.9gb
  5   1 open          55625 green      158265      7.5gb          3.7gb