表空间的自动扩展是文件单位的

首先看状况：

SQL> select file_id,file_name,tablespace_name,autoextensible from dba_data_files;

FILE_ID FILE_NAME                                          TABLESPACE AUTOEXTENS
------- -------------------------------------------------- ---------- ----------
      4 /u01/app/oracle/oradata/orcl/users01.dbf           USERS      YES
      3 /u01/app/oracle/oradata/orcl/undotbs01.dbf         UNDOTBS1   YES
      2 /u01/app/oracle/oradata/orcl/sysaux01.dbf          SYSAUX     YES
      1 /u01/app/oracle/oradata/orcl/system01.dbf          SYSTEM     YES
      5 /u01/app/oracle/oradata/orcl/example01.dbf         EXAMPLE    YES
      6 /u01/app/datafiles/gaodata1.dbf                    GAOTBS     YES

6 rows selected.

SQL>

然后，再来扩展表空间 GAOTBS:

SQL> alter tablespace gaotbs add datafile '/u01/app/datafiles/gaodata2.dbf' size 500M;

Tablespace altered.

然后，再看：

SQL> select file_id,file_name,tablespace_name,autoextensible from dba_data_files;

FILE_ID FILE_NAME                                          TABLESPACE AUTOEXTENS
------- -------------------------------------------------- ---------- ----------
      4 /u01/app/oracle/oradata/orcl/users01.dbf           USERS      YES
      3 /u01/app/oracle/oradata/orcl/undotbs01.dbf         UNDOTBS1   YES
      2 /u01/app/oracle/oradata/orcl/sysaux01.dbf          SYSAUX     YES
      1 /u01/app/oracle/oradata/orcl/system01.dbf          SYSTEM     YES
      5 /u01/app/oracle/oradata/orcl/example01.dbf         EXAMPLE    YES
      6 /u01/app/datafiles/gaodata1.dbf                    GAOTBS     YES
      7 /u01/app/datafiles/gaodata2.dbf                    GAOTBS     NO

7 rows selected.

SQL> select * from v$tablespace;     

 TS# NAME                                               INC BIG FLA ENC
---- -------------------------------------------------- --- --- --- ---
   0 SYSTEM                                             YES NO  YES
   1 SYSAUX                                             YES NO  YES
   2 UNDOTBS1                                           YES NO  YES
   4 USERS                                              YES NO  YES
   3 TEMP                                               NO  NO  YES
   6 EXAMPLE                                            YES NO  YES
   7 GAOTBS                                             YES NO  YES

7 rows selected.

SQL> desc v$tablespace;
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 TS#                                                NUMBER
 NAME                                               VARCHAR2(30)
 INCLUDED_IN_DATABASE_BACKUP                        VARCHAR2(3)
 BIGFILE                                            VARCHAR2(3)
 FLASHBACK_ON                                       VARCHAR2(3)
 ENCRYPT_IN_BACKUP                                  VARCHAR2(3)

SQL>