Fields

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The fields parameter is about fields that are explicitly marked as stored in the mapping, which is off by default and generally not recommended. Use 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.

{
    "fields" : ["user", "postDate"],
    "query" : {
        "term" : { "user" : "kimchy" }
    }
}

fields also accepts one or more wildcard patterns to control which fields of the document should be returned. WARNING: Only stored fields can be retrieved with wildcard patterns.

For example:

{
    "fields": ["xxx*", "*xxx", "*xxx*", "xxx*yyy", "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:

{
    "fields" : [],
    "query" : {
        "term" : { "user" : "kimchy" }
    }
}

For backwards compatibility, if the fields parameter specifies fields which are not stored (store mapping set to false), it will load the _source and extract it from it. This functionality has been replaced by the source filtering parameter.

Field values fetched from the document it self are always returned as an array. Metadata fields like _routing and _parent fields 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.