Dynamic field mapping
editDynamic field mapping
editWhen Elasticsearch detects a new field in a document, it dynamically adds the field to
the type mapping by default. The dynamic
parameter controls this behavior.
You can explicitly instruct Elasticsearch to dynamically create fields based on incoming
documents by setting the dynamic
parameter to true
or runtime
. When
dynamic field mapping is enabled, Elasticsearch uses the rules in the following table to
determine how to map data types for each field.
The field data types in the following table are the only field data types that Elasticsearch detects dynamically. You must explicitly map all other data types.
Elasticsearch data type |
||
JSON data type |
|
|
|
No field added |
No field added |
|
|
|
|
|
|
|
|
|
|
|
No field added |
|
Depends on the first non- |
Depends on the first non- |
|
|
|
|
|
|
|
|
|
You can disable dynamic mapping, both at the document and at the
object
level. Setting the dynamic
parameter to
false
ignores new fields, and strict
rejects the document if Elasticsearch
encounters an unknown field.
Use the update mapping API to update the dynamic
setting on existing fields.
You can customize dynamic field mapping rules for
date detection and numeric detection.
To define custom mappings rules that you can apply to additional dynamic
fields, use dynamic_templates
.
Date detection
editIf date_detection
is enabled (default), then new string fields are checked
to see whether their contents match any of the date patterns specified in
dynamic_date_formats
. If a match is found, a new date
field is
added with the corresponding format.
The default value for dynamic_date_formats
is:
[ "strict_date_optional_time"
,"yyyy/MM/dd HH:mm:ss Z||yyyy/MM/dd Z"
]
For example:
The |
Disabling date detection
editDynamic date detection can be disabled by setting date_detection
to false
:
PUT my-index-000001 { "mappings": { "date_detection": false } } PUT my-index-000001/_doc/1 { "create_date": "2015/09/02" }
The |
Customizing detected date formats
editAlternatively, the dynamic_date_formats
can be customized to support your
own date formats:
PUT my-index-000001 { "mappings": { "dynamic_date_formats": ["MM/dd/yyyy"] } } PUT my-index-000001/_doc/1 { "create_date": "09/25/2015" }
Numeric detection
editWhile JSON has support for native floating point and integer data types, some applications or languages may sometimes render numbers as strings. Usually the correct solution is to map these fields explicitly, but numeric detection (which is disabled by default) can be enabled to do this automatically: