Description of problem:

I have a view defined as follows:
CREATE VIEW U8 (IntKey integer,
    StringKey string,
    IntNum integer,
    StringNum string,
    FloatNum float,
    LongNum long,
    DoubleNum double,
    ByteNum byte,
    DateValue date,
    TimeValue time,
    TimestampValue timestamp,
    BooleanValue boolean,
    CharValue char,
    ShortValue short,
    BigIntegerValue biginteger,
    BigDecimalValue bigdecimal)
  AS
    SELECT BQT1.SmallA.IntKey, BQT1.SmallA.StringKey, BQT1.SmallA.IntNum, BQT1.SmallA.StringNum,
        BQT1.SmallA.FloatNum, BQT1.SmallA.LongNum, BQT1.SmallA.DoubleNum, BQT1.SmallA.ByteNum,
        BQT1.SmallA.DateValue, BQT1.SmallA.TimeValue, BQT1.SmallA.TimestampValue, BQT1.SmallA.BooleanValue,
        BQT1.SmallA.CharValue, BQT1.SmallA.ShortValue, BQT1.SmallA.BigIntegerValue, BQT1.SmallA.BigDecimalValue
    FROM BQT1.SmallA
    UNION
    SELECT BQT1.SmallB.IntKey, BQT1.SmallB.StringKey, BQT1.SmallB.IntNum, BQT1.SmallB.StringNum,
        BQT1.SmallB.FloatNum, BQT1.SmallB.LongNum, BQT1.SmallB.DoubleNum, BQT1.SmallB.ByteNum,
        BQT1.SmallB.DateValue, BQT1.SmallB.TimeValue, BQT1.SmallB.TimestampValue, BQT1.SmallB.BooleanValue,
        BQT1.SmallB.CharValue, BQT1.SmallB.ShortValue, BQT1.SmallB.BigIntegerValue, BQT1.SmallB.BigDecimalValue
    FROM BQT1.SmallB ORDER BY IntKey;

Query *SELECT StringNum FROM VQT.U8 GROUP BY StringNum* returns duplicate results (multiple null).