[[mapping-dynamic-mapping]]
== Dynamic Mapping

Default mappings allow generic mapping definitions to be automatically applied
to types that do not have mappings predefined. This is mainly done
thanks to the fact that the
<<mapping-object-type,object mapping>> and
namely the <<mapping-root-object-type,root
object mapping>> allow for schema-less dynamic addition of unmapped
fields.

The default mapping definition is a plain mapping definition that is
embedded within the distribution:

[source,js]
--------------------------------------------------
{
    "_default_" : {
    }
}
--------------------------------------------------

Pretty short, isn't it? Basically, everything is defaulted, especially the
dynamic nature of the root object mapping. The default mapping can be
overridden by specifying the `_default_` type when creating a new index.

The dynamic creation of mappings for unmapped types can be completely
disabled by setting `index.mapper.dynamic` to `false`.

The dynamic creation of fields within a type can be completely
disabled by setting the `dynamic` property of the type to `strict`.

Here is a <<indices-put-mapping,Put Mapping>> example that
disables dynamic field creation for a `tweet`:

[source,js]
--------------------------------------------------
$ curl -XPUT 'http://localhost:9200/twitter/_mapping/tweet' -d '
{
    "tweet" : {
        "dynamic": "strict",
        "properties" : {
            "message" : {"type" : "string", "store" : true }
        }
    }
}
'
--------------------------------------------------

Here is how we can change the default
<<mapping-date-format,date_formats>> used in the
root and inner object types:

[source,js]
--------------------------------------------------
{
    "_default_" : {
        "dynamic_date_formats" : ["yyyy-MM-dd", "dd-MM-yyyy", "date_optional_time"]
    }
}
--------------------------------------------------

[float]
=== Unmapped fields in queries

Queries and filters can refer to fields that don't exist in a mapping. Whether this
is allowed is controlled by the `index.query.parse.allow_unmapped_fields` setting.
This setting defaults to `true`. Setting it to `false` will disallow the usage of
unmapped fields in queries.

When registering a new <<search-percolate,percolator query>> or creating
a <<filtered,filtered alias>> then the `index.query.parse.allow_unmapped_fields` setting
is forcefully overwritten to disallowed unmapped fields.