Можно ли объединить следующие запросы или делать внутреннюю процедуру

SELECT DISTINCT * 
    FROM (
        SELECT DISTINCT(KEEP_ORGANIZATION) 
            FROM GOV_ETALON
            WHERE KEEP_ORGANIZATION IS NOT NULL 
        UNION ALL SELECT DISTINCT(STORED_ETALON) 
            FROM REGISTER_ETALON
            WHERE STORED_ETALON IS NOT NULL ) O, (
                SELECT MIN(YEAR_ETALON) AS MIN_YEAR, MAX(YEAR_ETALON) AS MAX_YEAR
                    FROM GOV_ETALON
    ) Y

SELECT DISTINCT *
    FROM (
        SELECT DISTINCT(KEEP_POSITION)
            FROM GOV_ETALON
            WHERE KEEP_POSITION IS NOT NULL
        UNION ALL SELECT DISTINCT(POSITION_PEOPLE)
            FROM USERS_DATA
            WHERE POSITION_PEOPLE IS NOT NULL
    ) P

SELECT DISTINCT *
    FROM (
        SELECT DISTINCT(KEEP_DEGREE)
            FROM GOV_ETALON
            WHERE KEEP_DEGREE IS NOT NULL
        UNION ALL SELECT DISTINCT(DEGREE)
            FROM USERS_DATA
            WHERE DEGREE IS NOT NULL
    ) D

SELECT DISTINCT *
    FROM (
        SELECT DISTINCT(KEEP_RANK)
            FROM GOV_ETALON
            WHERE KEEP_RANK IS NOT NULL
        UNION ALL SELECT DISTINCT(RANK)
            FROM USERS_DATA
            WHERE RANK IS NOT NULL 
    ) R