text: -- @author prabhd 
  -- @created 2012-12-05 12:00:00 
  -- @modified 2012-12-05 12:00:00 
  -- @tags dml 
  -- @db_name dmldb
  -- @description union_test22: UNION with limit
  \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 UNION ALL SELECT * FROM dml_union_s ORDER BY 1,2,3,4) foo LIMIT 10;
  SELECT COUNT(*) FROM dml_union_r;
  INSERT INTO dml_union_r SELECT * FROM (SELECT * FROM dml_union_r UNION ALL SELECT * FROM dml_union_s ORDER BY 1,2,3,4) foo LIMIT 10;
  SELECT COUNT(*) FROM dml_union_r;
  
  