SYS@ORCL>archive log file;
SP2-0718: illegal ARCHIVE LOG option
SYS@ORCL>archive log list;
Database log mode No Archive Mode
Automatic archival Disabled
Archive destination USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence 20
Current log sequence 22
SYS@ORCL>select tablespace_name,file_name from dba_data_files;


TABLESPACE_NAME FILE_NAME
-------------------- --------------------------------------------------
USERS /u01/app/oracle/oradata/ORCL/users01.dbf
SYSAUX /u01/app/oracle/oradata/ORCL/sysaux01.dbf
UNDOTBS1 /u01/app/oracle/oradata/ORCL/undotbs01.dbf
SYSTEM /u01/app/oracle/oradata/ORCL/system01.dbf
EXAMPLE /u01/app/oracle/oradata/ORCL/example01.dbf
TYGER1 /u01/app/oracle/oradata/ORCL/tyger1_01.dbf


6 rows selected.


SYS@ORCL>create tablespace tyger2 datafile '/u01/app/oracle/oradata/ORCL/tyger2_01.dbf' size 1m;


Tablespace created.


SYS@ORCL>drop user u2;


User dropped.


SYS@ORCL>create user u2 identified by u2 account unlock default tablespace tyger2;


User created.


SYS@ORCL>grant connect,resource,select any table to u2;


Grant succeeded.


SYS@ORCL>conn u2/u2
Connected.
U2@ORCL>create table u2_t as select * from scott.emp;


Table created.


U2@ORCL>commit;


Commit complete.


U2@ORCL>select count(*) from u2_t;


COUNT(*)
----------
14


U2@ORCL>conn / as sysdba
Connected.
SYS@ORCL>alter system switch logfile;


System altered.


SYS@ORCL>/


System altered.


......... 多切换几次
SYS@ORCL>/


System altered.


SYS@ORCL>shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SYS@ORCL>!
[oracle@tyger ORCL]$ ls
control01.ctl redo03.log standbylog6b.log tyger1_01.dbf
control02.ctl standbylog4a.log standbylog7a.log tyger2_01.dbf
control03.ctl standbylog4b.log standbylog7b.log undotbs01.dbf
example01.dbf standbylog5a.log sysaux01.dbf users01.dbf
redo01.log standbylog5b.log system01.dbf
redo02.log standbylog6a.log temp01.dbf
[oracle@tyger ORCL]$ rm -rf tyger2_01.dbf
[oracle@tyger ORCL]$ exit
exit


SYS@ORCL>startup
ORACLE instance started.


Total System Global Area 285212672 bytes
Fixed Size 1218992 bytes
Variable Size 171968080 bytes
Database Buffers 109051904 bytes
Redo Buffers 2973696 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 7 - see DBWR trace file
ORA-01110: data file 7: '/u01/app/oracle/oradata/ORCL/tyger2_01.dbf'

SYS@ORCL>alter database datafile 7 offline drop;


Database altered.


SYS@ORCL>alter database open;


Database altered.


SYS@ORCL>select count(*) from u2.u2_t;
select count(*) from u2.u2_t
*
ERROR at line 1:
ORA-00376: file 7 cannot be read at this time
ORA-01110: data file 7: '/u01/app/oracle/oradata/ORCL/tyger2_01.dbf'

SYS@ORCL>alter database create datafile 7 as '/u01/app/oracle/oradata/ORCL/tyger2_01.dbf';


Database altered.


SYS@ORCL>recover datafile 7;
ORA-00279: change 820758 generated at 03/03/2014 17:33:12 needed for thread 1
ORA-00289: suggestion :
/u01/app/oracle/flash_recovery_area/ORCL/archivelog/2014_03_03/o1_mf_1_22_%u_.ar
c
ORA-00280: change 820758 for thread 1 is in se