Comment 1 for bug 1240413

Below SQL is OK:

xtest=> show table tableC;
 COLUMN_NAME | SQL_DATA_TYPE | TYPE_NAME | IS_NULLABLE | KEY | DEFAULT
-------------+---------------+-----------+-------------+-----+---------
 id | 4 | INTEGER | YES | NO |
 stime | 93 | TIMESTAMP | YES | NO |
 val | -5 | BIGINT | YES | NO |
(3 rows)

xtest=> select * from tableC;
 id | stime | val
----+-------------------------+-------
  1 | 2013-10-16 16:56:20.953 | 11111
(1 row)
xtest=> select * from (select stime, val,val2,''::text as t1, ''::text as t2 from tableB
union
select stime, val,0::bigint as val2,''::text as t1, ''::text as t2 from tableC) t order by stime;
          stime | val | val2 | t1 | t2
-------------------------+-------+------------+----+----
 2013-10-16 16:09:05.078 | 67890 | 1234567890 | |
 2013-10-16 16:56:20.953 | 11111 | 0 | |
(2 rows)