How to know Payload Size of BPEL Instance Request Message

Please use below query ==>Payload Size of BPEL Instance Request Message

select DOCKEY, BIN_USIZE from orabpel.xml_document where dockey in (select dockey from orabpel.document_dlv_msg_ref where message_guid in (select message_guid from orabpel.invoke_message where message_guid in (select distinct(message_guid) from orabpel.invoke_message where process_id in ('BPELPROCESSNAME1','BPELPROCESSNAME2') and receive_date >= to_date('2012-10-07','YYYY-MM-DD') and receive_date < to_date('2012-10-08','YYYY-MM-DD'))))