[[mapper]]
== Mapper Plugins

Mapper plugins allow new field data types to be added to Elasticsearch.

[discrete]
=== Core mapper plugins

The core mapper plugins are:

<<mapper-size>>::

The mapper-size plugin provides the `_size` metadata field which, when enabled,
indexes the size in bytes of the original
{ref}/mapping-source-field.html[`_source`] field.

<<mapper-murmur3>>::

The mapper-murmur3 plugin allows hashes to be computed at index-time and stored
in the index for later use with the `cardinality` aggregation.

<<mapper-annotated-text>>::

The annotated text plugin provides the ability to index text that is a
combination of free-text and special markup that is typically used to identify
items of interest such as people or organisations (see NER or Named Entity Recognition
tools).

include::mapper-size.asciidoc[]
include::mapper-murmur3.asciidoc[]
include::mapper-annotated-text.asciidoc[]
