Delete all documents with dot in field name

Elastic Stack Elasticsearch
1

Hi! Can I delete all documents with dots in field name? Need it for ES upgrade.

2

Hi, would it be possible for you to copy your index in a new one, without the field or renamed ?

https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-reindex.html#docs-reindex-change-name

3

Well! The problem is - I don't really know how many fields with dot I have. I need something
if (any field content ".")
delete document

4

Ok, maybe you can do that with a delete-by-query (or update-by-query) and a script inside.

5

Note that removing all documents which contain a dot in a field name won't change the existing mapping.
I doubt it solves your migration concern.

Why not trying to upgrade to 5.1 directly using reindex from remote API?
5.x allows in certain conditions IIRC dots in field names.