[[root-object]] === The Root Object

The uppermost level of a mapping is known ((("mapping (types)", "root object")))((("root object")))as the root object. It may contain the following:

• A properties section, which lists the mapping for each field that a document may contain

• Various metadata fields, all of which start with an underscore, such as _type, _id, and _source

• Settings, which control how the dynamic detection of new fields is handled, such as analyzer, dynamic_date_formats, and dynamic_templates

• Other settings, which can be applied both to the root object and to fields of type object, such as enabled, dynamic, and include_in_all

==== Properties

We have already discussed the three most important settings for document fields or ((("root object", "properties")))((("properties", "important settings")))properties in <> and <>:

type:: The datatype that the field contains, such as string or date

index::
Whether a field should be searchable as full text (analyzed), searchable as an exact value (not_analyzed), or not searchable at all (no)

analyzer::
Which analyzer to use for a full-text field, both at index time and at search time

We will discuss other field types such as ip, geo_point, and geo_shape in the appropriate sections later in the book.

include::31_Metadata_source.asciidoc[]

include::32_Metadata_all.asciidoc[]

include::33_Metadata_ID.asciidoc[]