How to update/change the existing field type in a mapping of an index in elasticsearch using python?

Question

I am trying to update a field type in my existing index mappings but getting BadRequestError using put_mapping method. The same method works to add a new field but not to update an existing one. Is there any other method available for the same?

In the below example, i am trying to change the date format of start_time

es_client.indices.put_mapping(index='test-index',properties=properties)

This is the error i got

raise HTTP_EXCEPTIONS.get(meta.status, ApiError)(

elasticsearch.BadRequestError: BadRequestError(400, 'illegal_argument_exception', 'Mapper for [start_time] conflicts with existing mapper:\n\tCannot update parameter [format] from [yyyy-MM-dd HH:mm:ss||epoch_millis] to [yyyy-MM-dd HH:mm:ss]')

Answer 1

It is not possible to change the mapping after creation of index if you want to change the mapping you would need to use Re-indexing API, for more information check the answer here: Elastic search, no mappings with filters

Answer 2

as it has been mentioned above in the comments, you cannot change a mapping once the index has been created

you need to delete the index, then recreate it with the correct setting