SQL> conn / as sysdba
Connected.
SQL> select name from v$datafile where rownum=1;

NAME                                                                                               
------------------------------------------                                                         
F:\ORACLE\ORADATA\ORA9\SYSTEM01.DBF                                                                

SQL> create tablespace st datafile 'F:\ORACLE\ORADATA\ORA9\st1.dbf' size 2m;

Tablespace created.

SQL> alter tablespace st add datafile 'F:\ORACLE\ORADATA\ORA9\st2.dbf' size 2m;

Tablespace altered.

SQL> alter tablespace st add datafile 'F:\ORACLE\ORADATA\ORA9\st3.dbf' size 2m;

Tablespace altered.

SQL> create table scott.t1 tablespace st  as select * from scott.emp;

Table created.

SQL> select tablespace_name from dba_tables where table_name='T1' AND owner='SCOTT';

TABLESPACE_NAME                                                                                    
---------------                                                                                    
ST                                                                                                 

SQL> DESC DBA_EXTENTS
 Name                                                  Null?    Type
 ----------------------------------------------------- -------- ------------------------------------
 OWNER                                                          VARCHAR2(30)
 SEGMENT_NAME                                                   VARCHAR2(81)
 PARTITION_NAME                                                 VARCHAR2(30)
 SEGMENT_TYPE                                                   VARCHAR2(18)
 TABLESPACE_NAME                                                VARCHAR2(30)
 EXTENT_ID                                                      NUMBER
 FILE_ID                                                        NUMBER
 BLOCK_ID                                                       NUMBER
 BYTES                                                          NUMBER
 BLOCKS                                                         NUMBER
 RELATIVE_FNO                                                   NUMBER

SQL> SELECT EXTENT_ID,FILE_ID,BLOCK_ID,BLOCKS FROM DBA_EXTENTS
  2  where SEGMENT_NAME='T1' AND owner='SCOTT';

 EXTENT_ID    FILE_ID   BLOCK_ID     BLOCKS                                                        
---------- ---------- ---------- ----------                                                        
         0         12          9          8                                                        

SQL> SELECT FILE_ID,FILE_NAME FROM DBA_DATA_FILES WHERE TABLESPACE_NAME='ST';

   FILE_ID FILE_NAME                                                                               
---------- ----------------------------------------                                                
        11 F:\ORACLE\ORADATA\ORA9\ST1.DBF                                                          
        12 F:\ORACLE\ORADATA\ORA9\ST2.DBF                                                          
        13 F:\ORACLE\ORADATA\ORA9\ST3.DBF                                                          

SQL> ALTER TABLE SCOTT.T1 ALLOCATE EXTENT(DATAFILE 'F:\ORACLE\ORADATA\ORA9\ST1.DBF');

Table altered.

SQL> SELECT EXTENT_ID,FILE_ID,BLOCK_ID,BLOCKS FROM DBA_EXTENTS
  2  where SEGMENT_NAME='T1' AND owner='SCOTT';

 EXTENT_ID    FILE_ID   BLOCK_ID     BLOCKS                                                        
---------- ---------- ---------- ----------                                                        
         0         12          9          8                                                        
         1         11          9          8                                                        

SQL> ALTER TABLE SCOTT.T1 ALLOCATE EXTENT(DATAFILE 'F:\ORACLE\ORADATA\ORA9\ST3.DBF');

Table altered.

SQL>  SELECT EXTENT_ID,FILE_ID,BLOCK_ID,BLOCKS FROM DBA_EXTENTS
  2   where SEGMENT_NAME='T1' AND owner='SCOTT';

 EXTENT_ID    FILE_ID   BLOCK_ID     BLOCKS                                                        
---------- ---------- ---------- ----------                                                        
         0         12          9          8                                                        
         1         11          9          8                                                        
         2         13          9          8                    
提示：表的条带化的意义和IO相关。具体的深入的理解自己动手多做实验，加深理解！