Mapping

Flexible schema: index a document and field mappings will be derived automatically
Mapping defines how a document and its fields are stored and indexed
Mapping can be derived dynamically by ElasticSearch
A handful of core data types are supported
Mapping can be added to an existing index for new fields
Existing field mapping not always possible to modify

ElasticSearch will derive mapping for a new type and for new fields:

curl -XPOST localhost:9200/orders/_doc/1 \
  -H 'Content-Type: application/json' \
  -d '{"id": "1", "placedOn": "2016-10-17T13:03:30.830Z"}'

Retrieving existing mappings: curl 'localhost:9200/orders/_mapping?pretty=true'

Expected response:

{
  "orders" : {
    "mappings" : {
      "_doc" : {
        "properties" : {
          "id" : {
            "type" : "text",
            "fields" : {
              "keyword" : {
                "type" : "keyword",
                "ignore_above" : 256
              }
            }
          },
          "placedOn" : {
            "type" : "date"
          }
        }
      }
    }
  }
}

Rich support for date-time formats