_timestamp

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The _timestamp field allows to automatically index the timestamp of a document. It can be provided externally via the index request or in the _source. If it is not provided externally it will be automatically set to the date the document was processed by the indexing chain.

enabled

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By default it is disabled, in order to enable it, the following mapping should be defined:

{
    "tweet" : {
        "_timestamp" : { "enabled" : true }
    }
}

store / index

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By default the _timestamp field has store set to no and index set to not_analyzed. It can be queried as a standard date field.

path

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The _timestamp value can be provided as an external value when indexing. But, it can also be automatically extracted from the document to index based on a path. For example, having the following mapping:

{
    "tweet" : {
        "_timestamp" : {
            "enabled" : true,
            "path" : "post_date"
        }
    }
}

Will cause 2009-11-15T14:12:12 to be used as the timestamp value for:

{
    "message" : "You know, for Search",
    "post_date" : "2009-11-15T14:12:12"
}

Note, using path without explicit timestamp value provided require an additional (though quite fast) parsing phase.

format

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You can define the date format used to parse the provided timestamp value. For example:

{
    "tweet" : {
        "_timestamp" : {
            "enabled" : true,
            "path" : "post_date",
            "format" : "YYYY-MM-dd"
        }
    }
}

Note, the default format is dateOptionalTime. The timestamp value will first be parsed as a number and if it fails the format will be tried.