When you index a document that contains a new field, Search Enterprise adds the field dynamically to the document, or to the inner objects within a document. Inner objects inherit the dynamic setting from their parent object or from the mapping type. A dynamic parameter controls whether new fields are added dynamically. The default value is true and should be disabled to avoid a large index, unless a large index is necessary. This can be done when you create the index, using the following command:
curl -XPUT '<Search Enterprise URL>:<port>/<index name>?pretty' -H 'Content-Type: application/json' -d'
{
"mappings": {
"dynamic": "false"
}
}'