CREATE TABLE test( 
    item_data   XMLTYPE, 
    id          NUMBER 
)XMLTYPE COLUMN item_data STORE AS SECUREFILE BINARY XML

INSERT INTO test( 
    item_data, 
    id 
)VALUES( 
    '<ROWSET xml:space="preserve"> 
 <ROW> 
  <T1>t </T1> 
 </ROW> 
</ROWSET> 
', 
    1 
)

INSERT INTO test( 
    item_data, 
    id 
)VALUES( 
    '<ROWSET xml:space="preserve"> 
 <ROW> 
  <T1>t  </T1> 
 </ROW> 
</ROWSET> 
', 
    2 
)

INSERT INTO test( 
    item_data, 
    id 
)VALUES( 
    '<ROWSET xml:space="preserve"> 
 <ROW> 
  <T1/> 
 </ROW> 
</ROWSET> 
', 
    3 
)

INSERT INTO test( 
    item_data, 
    id 
)VALUES( 
    '<ROWSET xml:space="preserve"> 
 <ROW> 
  <T1>  </T1> 
 </ROW> 
</ROWSET> 
', 
    4 
)

SELECT 
    ucd.item_data, 
    ucd.item_data.getclobval(), 
    ucd."T1"   AS "T1", 
    id 
FROM 
    test x, 
    XMLTABLE('/ROWSET/ROW' PASSING x.item_data COLUMNS item_data XMLTYPE PATH '*',"T1" VARCHAR2(4000)PATH 'T1')ucd

DROP TABLE test