elasticsearch/docs/reference/migration/migrate_8_0/mappings.asciidoc

[float]
[[breaking_80_mappings_changes]]
=== Mapping changes

//NOTE: The notable-breaking-changes tagged regions are re-used in the
//Installation and Upgrade Guide

//tag::notable-breaking-changes[]

// end::notable-breaking-changes[]


.The maximum number of completion contexts per field is now 10.
[%collapsible]
====
*Details* +
The number of completion contexts within a single completion field
has been limited to 10.

*Impact* +
Use a maximum of 10 completion contexts in a completion field. Specifying more
than 10 completion contexts will return an error.
====


.Mapping API endpoints containing document types have been removed.
[%collapsible]
====
*Details* +
The typed REST endpoints of the Put Mapping, Get Mapping and Get Field mapping
APIs have been removed in favour of their typeless REST endpoints, since indexes
no longer contain types, these typed endpoints are obsolete.

*Impact* +
Use the typeless REST endpoints to update and retrieve mappings. Requests
submitted to the typed mapping API endpoints will return an error.
====

.Multi-fields within multi-fields is no longer supported.
[%collapsible]
====
*Details* +
Previously, it was possible to define a multi-field within a multi-field.
Defining chained multi-fields was deprecated in 7.3 and is now no longer
supported.

*Impact* +
To migrate mappings, all instances of `fields` that occur within
a `fields` block should be removed, either by flattening the chained `fields`
blocks into a single level, or by switching to `copy_to` if appropriate.
====

[[fieldnames-enabling]]
.The `_field_names` meta-field's `enabled` parameter has been removed.
[%collapsible]
====
*Details* +
The setting has been deprecated with 7.5 and is no longer supported on new indices.
Mappings for older indices will continue to work but emit a deprecation warning.

*Impact* +
The `enabled` setting for `_field_names` should be removed from templates and mappings. 
Disabling _field_names is not necessary because it no longer carries a large index overhead.
====