text: -- @author prabhd 
  -- @created 2012-12-05 12:00:00 
  -- @modified 2012-12-05 12:00:00 
  -- @tags dml 
  -- @db_name dmldb
  -- @description union_test10:  INSERT and EXCEPT operation
  \echo --start_ignore
  set gp_enable_column_oriented_table=on;
  \echo --end_ignore
  
  SELECT COUNT(*) FROM dml_union_r;
  SELECT COUNT(*) FROM (SELECT * FROM dml_union_r EXCEPT ALL SELECT dml_union_s.* FROM dml_union_s)foo;
  INSERT INTO dml_union_r SELECT * FROM dml_union_r EXCEPT ALL SELECT dml_union_s.* FROM dml_union_s;
  SELECT COUNT(*) FROM dml_union_r;
  
  