How to update index mapping with dynamic as strict in future?

Question

I am new to elastic search. I have an index named users, which has a lot of fields I know. But a few more fields can be added in the future.

So when defining my mapping, I want to include the fields that I know currently with dynamic "strict", but in the future, if I want to add the new field, how will update the new mapping and if I do it, will I have to reindex everything.

I found in the ES documents that mappings are applied only during index creation time. So I am a little confused here, what's the right way to approach this.

Answer 1

Inner objects inherit the dynamic setting from their parent object or from the mapping type. In the following example, dynamic mapping is disabled at the type level, so no new top-level fields will be added dynamically.

However, the user.social_networks object enables dynamic mapping, so you can add fields to this inner object.

https://www.elastic.co/guide/en/elasticsearch/reference/current/dynamic.html

PUT my-index-000001
{
  "mappings": {
    "dynamic": false, 
    "properties": {
      "user": { 
        "properties": {
          "name": {
            "type": "text"
          },
          "social_networks": {
            "dynamic": true, 
            "properties": {}
          }
        }
      }
    }
  }
}