SELECT MAIN1.diaMax as ELDIAMAXIMO, MAIN1.notes as LANOTAMAXIMA FROM ( select h.hst_date as diaMax, h.hst_note as notes from history as h WHERE h.hst_byr_usr_code='ascom' AND h.hst_ngt_code ='2' UNION select e.eml_date as diaMax, e.eml_subject as notes from email as e WHERE e.eml_ngt_code='2' ) as MAIN1 WHERE diaMax=( select MAX(SUBMAIN.diaMax2) FROM ( select h.hst_date as diaMax2 from history as h WHERE h.hst_byr_usr_code='ascom' AND h.hst_ngt_code ='2' UNION select e.eml_date as diaMax2 from email as e WHERE e.eml_ngt_code='2' ) as SUBMAIN )