[[mapping-size-field]] === `_size` The `_size` field allows to automatically index the size of the original `_source` indexed. By default, it's disabled. In order to enable it, set the mapping to: [source,js] -------------------------------------------------- { "tweet" : { "_size" : {"enabled" : true} } } -------------------------------------------------- In order to also store it, use: [source,js] -------------------------------------------------- { "tweet" : { "_size" : {"enabled" : true, "store" : "yes"} } } --------------------------------------------------