Configurei o parametro db_create_file_dest:
sql>ALTER SYSTEM SET DB_CREATE_FILE_DEST='/u01/app/oracle/oradata' SCOPE=BOTH;
Após isso criei uma tabela e inseri dados nela:
SQL> create table DGOMEZ6(id number primary key, value varchar2(20));
SQL> select b.file_id, b.file_name from dba_segments a, dba_data_files b where a.header_file=b.file_id and segment_name='DGOMEZ';
FILE ID FILE_NAME
----------- ---------------------------------------
11 /u01/app/oracle/oradata/ORCL/datafile/o1_mf_teste5_fqot4c86_.dbf
FILE_ID FILE_NAME
---------- --------------------------------------
4 +DATA/orcl/datafile/users.263.850528663