FULL OUTER JOIN converted to select with UNION ALL.

Oracle:

CREATE TABLE ORA.TEST_UPD_SEL1
 (
  COL3 BINARY_DOUBLE,
  COL4 BINARY_DOUBLE
  ) ; 
  
CREATE TABLE ORA.TEST_UPD_SEL
 ( 
COL1 BINARY_DOUBLE, 
COL2 BINARY_DOUBLE 
 ) ;
 
 select test_upd_sel.*, test_upd_sel1.* from test_upd_sel
 full outer join test_upd_sel1
 on test_upd_sel.col2=test_upd_sel1.col4;
 
 select test_upd_sel.col1, test_upd_sel1.col4 from test_upd_sel 
full join test_upd_sel1 
on test_upd_sel.col2=test_upd_sel1.col4;

select test_upd_sel.col5, test_upd_sel1.col4 from test_upd_sel 
full join test_upd_sel1 
on test_upd_sel.col2=test_upd_sel1.col4;

HiRDB:

CREATE TABLE ORA.TEST_UPD_SEL1
(
   COL3 FLOAT, 
   COL4 FLOAT 
);

CREATE TABLE ORA.TEST_UPD_SEL 
(
   COL1 FLOAT,
   COL2 FLOAT 
);

select test_upd_sel.*, test_upd_sel1.* from test_upd_sel left join test_upd_sel1 on test_upd_sel.col2=test_upd_sel1.col4
  union all 
select cast(null as float), cast(null as float), test_upd_sel1.* from test_upd_sel1 
 where not exists(select * from test_upd_sel where test_upd_sel.col2=test_upd_sel1.col4);
 
select test_upd_sel.col1, test_upd_sel1.col4 from test_upd_sel left join test_upd_sel1 on test_upd_sel.col2=test_upd_sel1.col4
  union all
select cast(null as float), test_upd_sel1.col4 from test_upd_sel1
 where not exists(select * from test_upd_sel where test_upd_sel.col2=test_upd_sel1.col4);
 
select test_upd_sel.col5, test_upd_sel1.col4 from test_upd_sel left join test_upd_sel1 on test_upd_sel.col2=test_upd_sel1.col4
  union all
select cast(null as datatype), test_upd_sel1.col4 from test_upd_sel1 
 where not exists(select * from test_upd_sel where test_upd_sel.col2=test_upd_sel1.col4);
 /* SQLWays: This conversion has inappropriate possibility */