OpenSearch/docs/reference/search/request/stored-fields.asciidoc

[[request-body-search-stored-fields]]
==== Stored Fields

WARNING: The `stored_fields` parameter is about fields that are explicitly marked as
stored in the mapping, which is off by default and generally not recommended.
Use <<request-body-search-source-filtering,source filtering>> instead to select
subsets of the original source document to be returned.

Allows to selectively load specific stored fields for each document represented
by a search hit.

[source,console]
--------------------------------------------------
GET /_search
{
    "stored_fields" : ["user", "postDate"],
    "query" : {
        "term" : { "user" : "kimchy" }
    }
}
--------------------------------------------------

`*` can be used to load all stored fields from the document.

An empty array will cause only the `_id` and `_type` for each hit to be
returned, for example:

[source,console]
--------------------------------------------------
GET /_search
{
    "stored_fields" : [],
    "query" : {
        "term" : { "user" : "kimchy" }
    }
}
--------------------------------------------------

If the requested fields are not stored (`store` mapping set to `false`), they will be ignored.

Stored field values fetched from the document itself are always returned as an array. On the contrary, metadata fields like `_routing` are never returned as an array.

Also only leaf fields can be returned via the `field` option. So object fields can't be returned and such requests
will fail.

Script fields can also be automatically detected and used as fields, so
things like `_source.obj1.field1` can be used, though not recommended, as
`obj1.field1` will work as well.

NOTE: On its own, `stored_fields` cannot be used to load fields in nested
objects -- if a field contains a nested object in its path, then no data will
be returned for that stored field. To access nested fields, `stored_fields`
must be used within an <<request-body-search-inner-hits, `inner_hits`>> block.

===== Disable stored fields entirely

To disable the stored fields (and metadata fields) entirely use: `_none_`:

[source,console]
--------------------------------------------------
GET /_search
{
    "stored_fields": "_none_",
    "query" : {
        "term" : { "user" : "kimchy" }
    }
}
--------------------------------------------------

NOTE: <<request-body-search-source-filtering,`_source`>> and <<request-body-search-version, `version`>> parameters cannot be activated if `_none_` is used.