Doc value Fields

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Allows to return the doc value representation of a field for each hit, for example:

GET /_search
{
    "query" : {
        "match_all": {}
    },
    "docvalue_fields" : [
        {
            "field": "my_ip_field", 
            "format": "use_field_mapping" 
        },
        {
            "field": "my_date_field",
            "format": "epoch_millis" 
        }
    ]
}

the name of the field

the special use_field_mapping format tells Elasticsearch to use the format from the mapping

date fields may use a custom format

Doc value fields can work on fields that are not stored.

* can be used as a wild card, for example:

GET /_search
{
    "query" : {
        "match_all": {}
    },
    "docvalue_fields" : [
        {
            "field": "*field", 
            "format": "use_field_mapping" 
        }
    ]
}

Match all fields ending with field

Format to be applied to all matching fields.

Note that if the fields parameter specifies fields without docvalues it will try to load the value from the fielddata cache causing the terms for that field to be loaded to memory (cached), which will result in more memory consumption.

Custom formats

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While most fields do not support custom formats, some of them do:

All fields support the special use_field_mapping format, which tells Elasticsearch to use the mappings to figure out a default format.

The default is currently to return the same output as script fields. However it will change in 7.0 to behave as if the use_field_mapping format was provided.

On its own, docvalue_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 docvalue field. To access nested fields, docvalue_fields must be used within an inner_hits block.