¿Estás usando UTF-16? + NVARCHAR2 ¿por casualidad? por ejemplo, esto:
SQL> select * from nls_database_parameters where parameter='NLS_NCHAR_CHARACTERSET';
PARAMETER VALUE
------------------------------ ----------------------------------------
NLS_NCHAR_CHARACTERSET AL16UTF16
SQL> drop table test;
Table dropped.
SQL> create table test(a nvarchar2(10));
Table created.
SQL> insert into test values ('test');
1 row created.
SQL> insert into test values ('test 2');
1 row created.
SQL> select listagg(a, ',') within group (order by 1) from test group by 1;
LISTAGG(A,',')WITHINGROUP(ORDERBY1)
--------------------------------------------------------------------------------
t e s t, t e s t 2
podría lanzar a un char para evitar esto. SI esto no es aceptable, debe generar un ticket con el soporte de Oracle.
SQL> select listagg(to_char(a),',') within group (order by 1) from test group by 1;
LISTAGG(TO_CHAR(A),',')WITHINGROUP(ORDERBY1)
--------------------------------------------------------------------------------
test,test 2
SQL>
