store
editstore
editBy default, field values are indexed to make them searchable, but they are not stored. This means that the field can be queried, but the original field value cannot be retrieved.
Usually this doesn’t matter. The field value is already part of the
_source
field, which is stored by default. If you
only want to retrieve the value of a single field or of a few fields, instead
of the whole _source
, then this can be achieved with
source filtering.
In certain situations it can make sense to store
a field. For instance, if
you have a document with a title
, a date
, and a very large content
field, you may want to retrieve just the title
and the date
without having
to extract those fields from a large _source
field:
PUT my_index { "mappings": { "_doc": { "properties": { "title": { "type": "text", "store": true }, "date": { "type": "date", "store": true }, "content": { "type": "text" } } } } } PUT my_index/_doc/1 { "title": "Some short title", "date": "2015-01-01", "content": "A very long content field..." } GET my_index/_search { "stored_fields": [ "title", "date" ] }
The |
|
This request will retrieve the values of the |
Stored fields returned as arrays
For consistency, stored fields are always returned as an array because there is no way of knowing if the original field value was a single value, multiple values, or an empty array.
If you need the original value, you should retrieve it from the _source
field instead.
Another situation where it can make sense to make a field stored is for those
that don’t appear in the _source
field (such as copy_to
fields).