If i install EasticSearch 6.4.1 and push some data to ElasticSearch . Now there are 3 indices . Then i will upgrade ElasticSearch to 6.6.1 and push some data, Now there are 5 indices.
My Question is if i rollback from ElasticSearch 6.6.1 to ElasticSearch 6.4.1 , Whether i will be getting 3 indices or 5 indices. My understanding is i will be getting all the 5 indices, 3 indices created by EasticSearch 6.4.1 and 2 indices created by EasticSearch 6.6.1.
Can you please explain me what happens to the data whenever roll back of ElasticSearch is done. Whether ElasticSearch Retains all the data or it retains data created under specific versions.