If you need to change the mapping of an elasticsearch index, then you have to remove it first and then re-create and re-index it again. Here is how you can do this in a Laravel application.
Here are a sample list for different operations you might need to do with elatsicsearch indices.
Im my case, I wanted to sort results of the general search based on the most recent parliament number, then the most recent session number. This is fine as far as both fields are already mapped for all indices. But when the field is missing, such as in my case the parliament number, then you shall direct the elasticsearch to know how he will be doing with these missing fields in other indices, So here is how to tell it :
I tries re-installing Elasticsearch 6.3.0 on my local server, and installed Java JDK, the most recent one, then when I try to start the Elasticsearch from installation folder/6.3.0/bin/elasticsearch.exe the cmd screen opens and immedietely closes. Here is the error : Unrecognized VM option 'UseConcMarkSweepGC'