数据文件管理
2015-03-30 00:02
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数据文件分2个方向管理：
物理结构和逻辑结构。
逻辑结构： 物理结构：
......................
表空间类型：system、sysaux、temp、undo、index、其他
创建表空间：
语法：create tablespace <name>
datafile '<dir>' size N[k|m|g|t];
创建表空间时我们需呀考虑几个问题：
1）具有create tablespace权限
2）smallfile和bigfile（T级以上：可以减少数据问文件个数，方便管理）：如果系统默认是存放smallfile，则创建表空间create tablespace相当于cteate smallfile tablespace；如果系统默认是存放bigfile，则创建表空间create tablespace相当于cteate bigfile tablespace；
如何查看系统默认创建表空间是smallfile还是bigfile文件，可以通过查询database_properties来查看，如下：可知现系统默认创建为smallfile表空间文件。
SQL> desc database_properties
?? ????? ??
----------------------------------------- -------- ----------------------------
PROPERTY_NAME NOT NULL VARCHAR2(30)
PROPERTY_VALUE VARCHAR2(4000)
DESCRIPTION VARCHAR2(4000)
SQL> col PROPERTY_NAME for a10;
SQL> col PROPERTY_value for a20;
SQL> select PROPERTY_NAME,PROPERTY_VALUE from database_properties where property_name like '%TBS%';
PROPERTY_NAME PROPERTY_VALUE
------------------------------ --------------------
DEFAULT_TBS_TYPE SMALLFILE
如果想修改系统默认创建表空间为bigfile文件，操作如下：
SQL> alter database set default bigfile tablespace;
Database alterd.
SQL> select PROPERTY_NAME,PROPERTY_VALUE from database_properties where property_name like '%TBS%';
PROPERTY_NAME PROPERTY_VALUE
------------------------------ --------------------
DEFAULT_TBS_TYPE BIGFILE
3）IO是否够用。
表空间管理方式（区管理方式）：
1）字典管理：已淘汰：extent management dictionary
2）本地管理：9i后（默认）：extent management local
8i—>10g的数据迁移需要研究？
查看本地管理方式：dba_tablespace
SQL> select tablespace_name,EXTENT_MANAGEMENT from dba_tablespaces;
TABLESPACE_NAME EXTENT_MAN
------------------------------ ----------
SYSTEM LOCAL
UNDOTBS1 LOCAL
SYSAUX LOCAL
TEMP LOCAL
USERS LOCAL
表空间状态：1）offline、2）online、3）read only、4）read write
默认情况下表空间状态为online和read write：
SQL> select file#,status,enabled from v$datafile;
FILE# STATUS ENABLED
---------- ------- -------------------------------------------
1 SYSTEM READ WRITE
2 ONLINE READ WRITE
3 ONLINE READ WRITE
4 ONLINE READ WRITE
SQL> select b.tablespace_name,a.file#,a.status,a.enabled from v$datafile a,dba_data_files b where a.file#=b.file_id;
TABLESPACE_NAME FILE# STATUS ENABLED
------------------------------ ---------- ------- -----------------------------------------------------------------
SYSTEM 1 SYSTEM READ WRITE
UNDOTBS1 2 ONLINE READ WRITE
SYSAUX 3 ONLINE READ WRITE
USERS 4 ONLINE READ WRITE
修改表空间状态：
SQL> alter tablespace users read only;
SQL> alter tablespace users read write;
SQL> alter tablespace users offline;
???????
SQL> alter tablespace users online;
???????
表空间的重命名：alter tablespace <ole_tablespace_name> rename to <new_tablespace_name>;
system、sysaux不能改名
undo、temp表空间可以改名但是同时要把参数文件改了，不建议改。
users表空间可以改名
其他自定义表空间可以根据自己要求改名。
SQL> create tablespace fi datafile '/u01/oracle/oradata/orcl/fi.dbf' size 10m;
???????
SQL> alter tablespace fi rename to f1;
???????
表空间大小管理：
1）表空间自动扩张：
可以通过dba_data_files表的AUTOEXTENSIBLE字段查询表空间文件是否为自动扩张。
SQL> select tablespace_name,file_name,AUTOEXTENSIBLE from dba_data_files;
TABLESPACE FILE_NAME AUT
---------- -------------------------------------------------- ---
SYSTEM /u01/oracle/oradata/rezin/system01.dbf YES
UNDOTBS1 /u01/oracle/oradata/rezin/undotbs01.dbf YES
SYSAUX /u01/oracle/oradata/rezin/sysaux01.dbf YES
USERS /u01/oracle/oradata/rezin/users01.dbf YES
F1 /u01/oracle/oradata/orcl/fi.dbf NO
通过以上查询可知，只有F1表空间为非自动扩张状态，将其改为自动扩张表空间：
语法：SQL> alter database <路径>|<编号> autoextend on next nM maxsize Ng|t;
SQL> alter database datafile '/u01/oracle/oradata/orcl/fi.dbf' autoextend on;
SQL> select tablespace_name,file_name,AUTOEXTENSIBLE from dba_data_files;
TABLESPACE FILE_NAME AUT
---------- -------------------------------------------------- ---
SYSTEM /u01/oracle/oradata/rezin/system01.dbf YES
UNDOTBS1 /u01/oracle/oradata/rezin/undotbs01.dbf YES
SYSAUX /u01/oracle/oradata/rezin/sysaux01.dbf YES
USERS /u01/oracle/oradata/rezin/users01.dbf YES
F1 /u01/oracle/oradata/orcl/fi.dbf YES
2）手工resize数据文件大小
SQL> alter database datafile '/u01/oracle/oradata/orcl/fi.dbf' autoextend off;
SQL> alter database datafile '/u01/oracle/oradata/orcl/fi.dbf' resize 100m;
???????
3）添加数据文件（打开自动扩张）
SQL> alter tablespace f1 add datafile '/u01/oracle/oradata/orcl/f2.dbf' size 10m autoextend on next 10m maxsize 100m;
表空间数据文件的重命名和重定位：
条件：数据库在mount阶段或open阶段，归档模式，数据文件必须可以offline状态，如果数据文件不能offline，只能在mount状态重命名。
步骤：1）将要改名的表空间数据文件offline
2）操作系统级别移动数据文件（改名）
3）执行从命名命令
SQL> alter database rename file '<oldname>' to '<newname>';
4）将数据文件状态改为online状态。
SQL> alter tablespace f1 offline;
???????
SQL> ho cp /u01/oracle/oradata/orcl/f2.dbf /u01/oracle/oradata/orcl/f1.dbf
SQL> alter database rename file '/u01/oracle/oradata/orcl/f2.dbf'
to '/u01/oracle/oradata/orcl/f1.dbf';
???????
SQL> alter tablespace f1 online;
???????
删除表空间：
语法：drop tablespace <name> including contents and datafiles;
SQL> drop tablespace f1;
重新创建表空间：
SQL> create tablespace f2 datafile '/u01/oracle/oradata/orcl/f1.dbf' reuse;
???????
SQL> drop tablespace f2 including contents and datafiles;
???????
获取表空间和数据文件信息（数据文件相关视图）：
表空间信息：
dba_tablespace
v$tablespace
数据文件信息：
dba_data_files
v$datafile
临时数据文件信息：
dba_temp_files
v$tempfile
1）空间管理：一般放单个文件最好,看磁盘空间是否够用等
2）备份：归档模式备份，非归档模式只能冷备。
热备：A)alter tablespace system begin backup;
B)$cp '<system dir>' /bak
C)alter tablespace system end backup;
rman备份：back tablespace system;
[oracle@localhost ~]$ rman target /
Recovery Manager: Release 10.2.0.1.0 - Production on Wed Mar 18 09:31:40 2015
Copyright (c) 1982, 2005, Oracle. All rights reserved.
connected to target database: REZIN (DBID=633392282)
RMAN> backup tablespace system;
3）system异常处理：
A非归档、无备份-->不能恢复
无法恢复
B归档、有备份、日志完整--->可以恢复
热备文件恢复：
SQL> startup
ORACLE instance started.
Total System Global Area 285212672 bytes
Fixed Size 1218968 bytes
Variable Size 96470632 bytes
Database Buffers 180355072 bytes
Redo Buffers 7168000 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 1 - see DBWR trace file
ORA-01110: data file 1: '/u01/oracle/oradata/orcl/system01.dbf'
SQL> ho ls /u01/oracle/oradata/orcl/system01.dbf
ls: /u01/oracle/oradata/orcl/system01.dbf: 没有那个文件或目录
SQL> alter database open;
alter database open
*
ERROR at line 1:
ORA-01113: file 1 needs media recovery
ORA-01110: data file 1: '/u01/oracle/oradata/orcl/system01.dbf'
SQL> recover database;
Media recovery complete.
SQL> alter database open;
Database altered.
rman恢复：
RMAN> list backup；
RMAN> restore tablespace system;
Starting restore at 19-MAR-15
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=155 devtype=DISK
channel ORA_DISK_1: starting datafile backupset restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to /u01/oracle/oradata/orcl/system01.dbf
channel ORA_DISK_1: reading from backup piece /u01/oracle/flash_recovery_area/ORCL/backupset/2015_03_19/o1_mf_nnndf_TAG20150319T175033_bjo6zc4b_.bkp
channel ORA_DISK_1: restored backup piece 1
piece handle=/u01/oracle/flash_recovery_area/ORCL/backupset/2015_03_19/o1_mf_nnndf_TAG20150319T175033_bjo6zc4b_.bkp tag=TAG20150319T175033
channel ORA_DISK_1: restore complete, elapsed time: 00:00:35
Finished restore at 19-MAR-15
RMAN> recover tablespace system;
Starting recover at 19-MAR-15
using channel ORA_DISK_1
starting media recovery
media recovery complete, elapsed time: 00:00:05
Finished recover at 19-MAR-15
RMAN> sql 'alter database open';
sql statement: alter database open
RMAN>
C归档、有备份、日志不完整--->可以恢复，但不保证数据丢失
4、system表空间不能offline，不能read only，不能改名
sysaux表空间名字不能更改，不能drop，不能read only，能够offline
查询sysaux表空间下有哪些工具：
SQL> desc v$sysaux_occupants
Name Null? Type
----------------------------------------- -------- ----------------------------
OCCUPANT_NAME VARCHAR2(64)
OCCUPANT_DESC VARCHAR2(64)
SCHEMA_NAME VARCHAR2(64)
MOVE_PROCEDURE VARCHAR2(64)
MOVE_PROCEDURE_DESC VARCHAR2(64)
SPACE_USAGE_KBYTES NUMBER
SQL> col OCCUPANT_NAME for a20;
SQL> col SCHEMA_NAME for a20;
SQL> select OCCUPANT_NAME, SCHEMA_NAME from v$sysaux_occupants;
OCCUPANT_NAME SCHEMA_NAME
-------------------- --------------------
LOGMNR SYSTEM
LOGSTDBY SYSTEM
STREAMS SYS
XDB XDB
AO SYS
XSOQHIST SYS
XSAMD OLAPSYS
SM/AWR SYS
SM/ADVISOR SYS
SM/OPTSTAT SYS
SM/OTHER SYS
STATSPACK PERFSTAT
ODM DMSYS
SDO MDSYS
WM WMSYS
ORDIM ORDSYS
ORDIM/PLUGINS ORDPLUGINS
ORDIM/SQLMM SI_INFORMTN_SCHEMA
EM SYSMAN
TEXT CTXSYS
ULTRASEARCH WKSYS
ULTRASEARCH_DEMO_USE WK_TEST
EXPRESSION_FILTER EXFSYS
EM_MONITORING_USER DBSNMP
TSM TSMSYS
JOB_SCHEDULER SYS
26 rows selected.
备份：归档（非归档只能冷备，无大意义）可以热备也可以rman备份。
热备：A)alter tablespace sysaux begin backup;
B)$cp '<system dir>' /bak
C)alter tablespace sysaux end backup;
rman备份：back tablespace sysaux;
[oracle@localhost ~]$ rman target /
Recovery Manager: Release 10.2.0.1.0 - Production on Wed Mar 18 09:31:40 2015
Copyright (c) 1982, 2005, Oracle. All rights reserved.
connected to target database: REZIN (DBID=633392282)
RMAN> back tablespace sysaux;
sysaux表空间的异常处理：
1）有备份--->还原，恢复
使用热备文件恢复：
SQL> startup
ORACLE instance started.
Total System Global Area 285212672 bytes
Fixed Size 1218968 bytes
Variable Size 79693416 bytes
Database Buffers 197132288 bytes
Redo Buffers 7168000 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 3 - see DBWR trace file
ORA-01110: data file 3: '/u01/oracle/oradata/orcl/sysaux01.dbf'
SQL> ho cp /u01/oracle/sysaux01.dbf /u01/oracle/oradata/orcl/sysaux01.dbf
SQL> alter database open;
alter database open
*
ERROR at line 1:
ORA-01113: file 3 needs media recovery
ORA-01110: data file 3: '/u01/oracle/oradata/orcl/sysaux01.dbf'
SQL> recover database;
Media recovery complete.
SQL> alter database open;
Database altered.
rman备份恢复：
[oracle@localhost ~]$ rman target /
RMAN> list backup;
RMAN> restore tablespace sysaux;
Starting restore at 20-MAR-15
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=155 devtype=DISK
channel ORA_DISK_1: starting datafile backupset restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
restoring datafile 00003 to /u01/oracle/oradata/orcl/sysaux01.dbf
channel ORA_DISK_1: reading from backup piece /u01/oracle/flash_recovery_area/ORCL/backupset/2015_03_20/o1_mf_nnndf_TAG20150320T054421_bjpjsot8_.bkp
channel ORA_DISK_1: restored backup piece 1
piece handle=/u01/oracle/flash_recovery_area/ORCL/backupset/2015_03_20/o1_mf_nnndf_TAG20150320T054421_bjpjsot8_.bkp tag=TAG20150320T054421
channel ORA_DISK_1: restore complete, elapsed time: 00:00:16
Finished restore at 20-MAR-15
RMAN> recover tablespace sysaux;
Starting recover at 20-MAR-15
using channel ORA_DISK_1
starting media recovery
media recovery complete, elapsed time: 00:00:02
Finished recover at 20-MAR-15
RMAN> sql 'alter database open';
sql statement: alter database open
RMAN>
2）无备份--->offline sysaux表空间，然后迁移数据，再重新建库，将数据迁移回来。
无备份下sysaux表空间损坏如何打开数据库：
1）事务的回退：rollback
2）事务的恢复：撤销没有提交的内容
3）读一致性：事务只能查询自己修改过的内容或是原来的内容（锁的作用）。
4）闪回数据：查询3600面之前的数据
undo表空间管理模式/undo表空间参数：自动/手动，由undo_management参数决定undo表空间管理模式。
查询undo表空间管理模式：
SQL> show parameter undo_m
NAME TYPE VALUE
------------------------------------ ---------- -----------------------------------------------------
undo_management string AUTO
查询系统使用的默认undo表空间：
SQL> show parameter undo_t
NAME TYPE VALUE
------------------------------------ ---------- ------------------------------
undo_tablespace string UNDOTBS1
undo表空间段类型：
1）系统段：存放系统表空间产生的镜像数据。
2）非系统段：存放非系统表空间产生的镜像数据。
3）临时段：能够offline的表空间产生，记录offline阶段oracle数据库产生的数据。
查询如下视图：查寻系统段和非系统段通过v$rollname
SQL> select * from v$rollname;
USN NAME
---------- --------------------------
0 SYSTEM
1 _SYSSMU1$
2 _SYSSMU2$
3 _SYSSMU3$
4 _SYSSMU4$
5 _SYSSMU5$
6 _SYSSMU6$
7 _SYSSMU7$
8 _SYSSMU8$
9 _SYSSMU9$
10 _SYSSMU10$
11 rows selected.
查询临时段通过dba_segments：
SQL> ALTER tablespace users offline;
Tablespace altered.
SQL> col SEGMENT_NAME for a20;
SQL> col SEGMENT_TYPE for a20;
SQL> select segment_name,segment_type from dba_segments where segment_type like '%DEF%';
SEGMENT_NAME SEGMENT_TYPE
-------------------- --------------------
1.60881 DEFERRED ROLLBACK
查询undo表空间保存历史数据最久多少：
SQL> show parameter undo_r
NAME TYPE VALUE
------------------------------------ ---------- ------------------------------
undo_retention integer 900
undo表空间建立、删除、更改：
1）建立：建库时自动建立
手工建立：SQL>create smallfile|bigfile undo tablespace <name> datafile <dir> size <size> autoextend on next size <size> maxsize <size>;
SQL> create undo tablespace undo1 datafile '/u01/oracle/oradata/orcl/undo1.dbf' size 100m autoextend on;
Tablespace created.
2）删除：drop tablespace <undoname> including contents and datafile;
3）更改：alter system set audo_tablespace=<undo_name>;
OR
SQL>alter tablespace undotbs1 tename to undotbs;
SQL>shutdown immediate
SQL>startup
估算undo表空间该设为多大大小：
公式：undo space=(undo_retention*(undo blocks per second*db block size))+db block_size
SQL> show parameter undo_retention
NAME TYPE VALUE
------------------------------------ ---------- ------------------------------
undo_retention integer 900
SQL> select sum(undoblks)/sum((end_time-begin_time)*10800) from v$undostat;
SUM(UNDOBLKS)/SUM((END_TIME-BEGIN_TIME)*10800)
----------------------------------------------
1.98037077
SQL> select 900* 1.98037077*8192 from dual;
900*1.98037077*8192
-----------------------------------------
14600877.6
查询undo表空间当前分配大小：
1）SQL> select max(block_id) from dba_extents where file_id=2;
MAX(BLOCK_ID)
-------------
4617
2）SQL> select 4617*8192/1024/1024||'G' from dual;
4617*8192/1
-----------------------------
36.0703125G
作用：可以将undo表空间容量变小。
undo的资料查询：（47后半部分）
1）SQL> desc dba_rollback_segs
Name Null? Type
----------------------------------------- -------- ----------------------------
SEGMENT_NAME NOT NULL VARCHAR2(30)
OWNER VARCHAR2(6)
TABLESPACE_NAME NOT NULL VARCHAR2(30)
SEGMENT_ID NOT NULL NUMBER
FILE_ID NOT NULL NUMBER
BLOCK_ID NOT NULL NUMBER
INITIAL_EXTENT NUMBER
NEXT_EXTENT NUMBER
MIN_EXTENTS NOT NULL NUMBER
MAX_EXTENTS NOT NULL NUMBER
PCT_INCREASE NUMBER
STATUS VARCHAR2(16)
INSTANCE_NUM VARCHAR2(40)
RELATIVE_FNO NOT NULL NUMBER
SQL> select TABLESPACE_NAME,SEGMENT_NAME,FILE_ID from dba_rollback_segs;
2）SQL> desc v$rollname
Name Null? Type
----------------------------------------- -------- ----------------------------
USN NUMBER
NAME NOT NULL VARCHAR2(30)
SQL> select * from v$rollname;
USN NAME
---------- ----------
0 SYSTEM
1 _SYSSMU1$
2 _SYSSMU2$
3 _SYSSMU3$
4 _SYSSMU4$
5 _SYSSMU5$
6 _SYSSMU6$
7 _SYSSMU7$
8 _SYSSMU8$
9 _SYSSMU9$
10 _SYSSMU10$
11 rows selected.
3）SQL> desc v$rollstat;
Name Null? Type
----------------------------------------- -------- ----------------------------
USN NUMBER
LATCH NUMBER
EXTENTS NUMBER
RSSIZE NUMBER
WRITES NUMBER
XACTS NUMBER
GETS NUMBER
WAITS NUMBER
OPTSIZE NUMBER
HWMSIZE NUMBER
SHRINKS NUMBER
WRAPS NUMBER
EXTENDS NUMBER
AVESHRINK NUMBER
AVEACTIVE NUMBER
STATUS VARCHAR2(15)
CUREXT NUMBER
CURBLK NUMBER
4）SQL> desc dba_segments
Name Null? Type
----------------------------------------- -------- ----------------------------
OWNER VARCHAR2(30)
SEGMENT_NAME VARCHAR2(81)
PARTITION_NAME VARCHAR2(30)
SEGMENT_TYPE VARCHAR2(18)
TABLESPACE_NAME VARCHAR2(30)
HEADER_FILE NUMBER
HEADER_BLOCK NUMBER
BYTES NUMBER
BLOCKS NUMBER
EXTENTS NUMBER
INITIAL_EXTENT NUMBER
NEXT_EXTENT NUMBER
MIN_EXTENTS NUMBER
MAX_EXTENTS NUMBER
PCT_INCREASE NUMBER
FREELISTS NUMBER
FREELIST_GROUPS NUMBER
RELATIVE_FNO NUMBER
BUFFER_POOL VARCHAR2(7)
5）SQL> desc v$transaction
Name Null? Type
----------------------------------------- -------- ----------------------------
ADDR RAW(4)
XIDUSN NUMBER
XIDSLOT NUMBER
XIDSQN NUMBER
UBAFIL NUMBER
UBABLK NUMBER
UBASQN NUMBER
UBAREC NUMBER
STATUS VARCHAR2(16)
START_TIME VARCHAR2(20)
START_SCNB NUMBER
START_SCNW NUMBER
START_UEXT NUMBER
START_UBAFIL NUMBER
START_UBABLK NUMBER
START_UBASQN NUMBER
START_UBAREC NUMBER
SES_ADDR RAW(4)
FLAG NUMBER
SPACE VARCHAR2(3)
RECURSIVE VARCHAR2(3)
NOUNDO VARCHAR2(3)
PTX VARCHAR2(3)
NAME VARCHAR2(256)
PRV_XIDUSN NUMBER
PRV_XIDSLT NUMBER
PRV_XIDSQN NUMBER
PTX_XIDUSN NUMBER
PTX_XIDSLT NUMBER
PTX_XIDSQN NUMBER
DSCN-B NUMBER
DSCN-W NUMBER
USED_UBLK NUMBER
USED_UREC NUMBER
LOG_IO NUMBER
PHY_IO NUMBER
CR_GET NUMBER
CR_CHANGE NUMBER
START_DATE DATE
DSCN_BASE NUMBER
DSCN_WRAP NUMBER
START_SCN NUMBER
DEPENDENT_SCN NUMBER
XID RAW(8)
PRV_XID RAW(8)
PTX_XID RAW(8)
undo表空间的应用：
1）事务的回退：事务没有结束之前才能执行。
SQL>rollback;
SQL> show user
USER is "SCOTT"
SQL> delete from emp where deptno=10;
3 rows deleted
SQL> savepoint s1;
Savepoint created.
SQL> delete from emp where deptno=20;
5 rows deleted.
SQL> savepoint s2;
Savepoint created.
SQL> delete from emp where deptno=30;
6 rows deleted.
SQL> savepoint s3;
Savepoint created.
SQL> select * from emp;
no rows selected
SQL> rollback to s2;
Rollback complete.
SQL> select * from emp;
EMPNO ENAME JOB MGR HIREDATE SAL COMM
---------- ---------- --------- ---------- --------- ---------- ----------
DEPTNO
----------
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300
30
7521 WARD SALESMAN 7698 22-FEB-81 1250 500
30
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400
30
7698 BLAKE MANAGER 7839 01-MAY-81 2850
30
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0
30
7900 JAMES CLERK 7698 03-DEC-81 950
30
6 rows selected.
SQL> rollback to s1;
Rollback complete.
SQL> select * from emp;
EMPNO ENAME JOB MGR HIREDATE SAL COMM
---------- ---------- --------- ---------- --------- ---------- ----------
DEPTNO
----------
7369 SMITH CLERK 7902 17-DEC-80 800
20
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300
30
7521 WARD SALESMAN 7698 22-FEB-81 1250 500
30
7566 JONES MANAGER 7839 02-APR-81 2975
20
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400
30
7698 BLAKE MANAGER 7839 01-MAY-81 2850
30
7788 SCOTT ANALYST 7566 19-APR-87 3000
20
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0
30
7876 ADAMS CLERK 7788 23-MAY-87 1100
20
7900 JAMES CLERK 7698 03-DEC-81 950
30
7902 FORD ANALYST 7566 03-DEC-81 3000
20
11 rows selected.
2）事务的提交：自动或手工结束事务。
commit或是执行ddl语句或者设置数据库自动提交。
SQL> commit;
Commit complete.
3）闪回数据：
SQL> insert into emp select * from emp as of timestamp sysdate-5/1440;
14 rows created.
undo备份：
热备：A)alter tablespace undotbs1 begin backup;
B)$cp '<undotbs1 dir>' /bak
C)alter tablespace undotbs1 end backup;
rman备份：
rman备份：back tablespace undotbs1;
[oracle@localhost ~]$ rman target /
Recovery Manager: Release 10.2.0.1.0 - Production on Wed Mar 18 09:31:40 2015
Copyright (c) 1982, 2005, Oracle. All rights reserved.
connected to target database: REZIN (DBID=633392282)
RMAN> back tablespace undotbs1;
恢复：
[oracle@localhost ~]$ rman target /
Recovery Manager: Release 10.2.0.1.0 - Production on Sat Mar 21 00:28:34 2015
Copyright (c) 1982, 2005, Oracle. All rights reserved.
connected to target database: ORCL (DBID=1402521782, not open)
RMAN> restore tablespace undotbs1;
Starting restore at 21-MAR-15
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=156 devtype=DISK
channel ORA_DISK_1: starting datafile backupset restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
restoring datafile 00002 to /u01/oracle/oradata/orcl/undotbs01.dbf
channel ORA_DISK_1: reading from backup piece /u01/oracle/flash_recovery_area/ORCL/backupset/2015_03_21/o1_mf_nnndf_TAG20150321T002210_bjrl9mqr_.bkp
channel ORA_DISK_1: restored backup piece 1
piece handle=/u01/oracle/flash_recovery_area/ORCL/backupset/2015_03_21/o1_mf_nnndf_TAG20150321T002210_bjrl9mqr_.bkp tag=TAG20150321T002210
channel ORA_DISK_1: restore complete, elapsed time: 00:00:07
Finished restore at 21-MAR-15
RMAN> recover tablespace undotbs1;
Starting recover at 21-MAR-15
using channel ORA_DISK_1
starting media recovery
media recovery complete, elapsed time: 00:00:02
Finished recover at 21-MAR-15
SQL> alter database datafile 2 online;
Database altered.
SQL> alter database open;
Database altered.
无备份情况下的恢复：（48集）
1）系统中是否存在其他的undo表空间，如果存在，则替换其他的undo表空间，并且将损坏的undo表空间脱机，然后启动数据库到open阶段，再删除损坏的undo表空间，然后建立新的undo表空间。
2）系统中没有其他的undo表空间，使用隐藏参数，让undo表空间offline，打开数据库，再删除损坏undo表空间，然后再建立新的undo表空间。
无备份情况下的恢复步骤：
附：dml语句执行过程图解：
如何指定用户的默认表空间：
查询用户默认用户表空间：database_properties
SQL> select PROPERTY_NAME,PROPERTY_VALUE from database_properties where property_name like '%DEF%';
PROPERTY_NAME PROPERTY_VALUE
----------------------------------- ------------------------------
DEFAULT_TEMP_TABLESPACE TEMP
DEFAULT_PERMANENT_TABLESPACE USERS
DEFAULT_TBS_TYPE SMALLFILE
修改用户默认表空间：
SQL> alter database default tablespace users1;
Database altered.
结果如下：
SQL> select PROPERTY_NAME,PROPERTY_VALUE from database_properties where property_name like '%DEF%';
PROPERTY_NAME PROPERTY_VALUE
----------------------------------- ------------------------------
DEFAULT_TEMP_TABLESPACE TEMP
DEFAULT_PERMANENT_TABLESPACE USERS1
DEFAULT_TBS_TYPE SMALLFILE
users表空间备份：包括用户自定义的表孔间备份方法
热备：A)alter tablespace users begin backup;
B)$cp '<system dir>' /bak
C)alter tablespace users end backup;
rman备份：back tablespace users;
[oracle@localhost ~]$ rman target /
Recovery Manager: Release 10.2.0.1.0 - Production on Wed Mar 18 09:31:40 2015
Copyright (c) 1982, 2005, Oracle. All rights reserved.
connected to target database: REZIN (DBID=633392282)
RMAN> back tablespace users;
users表空间恢复：包括用户自定义的表孔间还原方法
1）热备还原：
SQL> ho cp /u01/oracle/users01.dbf /u01/oracle/oradata/orcl/users01.dbf
SQL> recover tablespace users;
Media recovery complete.
SQL> alter database open;
Database altered.
2）rman还原
RMAN>restore tablespace users;
RMAN>recover tablespace users;
SQL>alter tablespace users online;
3）用户自定义表空间，无备份，归档模式下，表空间创建以来日志文件全恢复方法：
alter database create datafile N as '<dir>';
SQL> alter tablespace users1 offline;
alter tablespace users1 offline
*
ERROR at line 1:
ORA-01116: error in opening database file 6
ORA-01110: data file 6: '/u01/oracle/oradata/orcl/user1.dbf'
ORA-27041: unable to open file
Linux Error: 2: No such file or directory
Additional information: 3
SQL> alter database datafile 6 offline;
Database altered.
SQL> alter database create datafile 6 as '/u01/oracle/oradata/orcl/user1.dbf';
Database altered.
SQL> recover tablespace users1;
Media recovery complete.
SQL> alter tablespace users1 online;
Tablespace altered.
SQL> select * from u1.u;
I
----------
1
1
1
附加：如果以上办法还是不能恢复users1表空间，则表示该表空间不能恢复，我们只能舍弃该表空间中的数据：即脱机数据文件。
SQL>alter database datafile <name> offline;
如何指定用户的默认临时表空间：
查询用户默认用户表空间：database_properties
SQL> select PROPERTY_NAME,PROPERTY_VALUE from database_properties where property_name like '%DEF%';
PROPERTY_NAME PROPERTY_VALUE
----------------------------------- ------------------------------
DEFAULT_TEMP_TABLESPACE TEMP
DEFAULT_PERMANENT_TABLESPACE USERS
DEFAULT_TBS_TYPE SMALLFILE
修改用户默认表空间：
SQL> alter database default temporary tablespace temp1;
Database altered.
结果如下：
SQL> select PROPERTY_NAME,PROPERTY_VALUE from database_properties where property_name like '%DEF%';
PROPERTY_NAME PROPERTY_VALUE
----------------------------------- ------------------------------
DEFAULT_TEMP_TABLESPACE TEMP1
DEFAULT_PERMANENT_TABLESPACE USERS
DEFAULT_TBS_TYPE SMALLFILE
1建立temp表空间
SQL> create temporary tablespace temp1 tempfile '/u01/oracle/oradata/orcl/temp1.dbf' size 100m;
Tablespace created.
查询系统下的临时表空间：desc dba_temp_files、v$tempfile
SQL> desc dba_temp_files
Name Null? Type
----------------------------------------- -------- ----------------------------
FILE_NAME VARCHAR2(513)
FILE_ID NUMBER
TABLESPACE_NAME NOT NULL VARCHAR2(30)
BYTES NUMBER
BLOCKS NUMBER
STATUS CHAR(9)
RELATIVE_FNO NUMBER
AUTOEXTENSIBLE VARCHAR2(3)
MAXBYTES NUMBER
MAXBLOCKS NUMBER
INCREMENT_BY NUMBER
USER_BYTES NUMBER
USER_BLOCKS NUMBER
SQL> desc v$tempfile
Name Null? Type
----------------------------------------- -------- ----------------------------
FILE# NUMBER
CREATION_CHANGE# NUMBER
CREATION_TIME DATE
TS# NUMBER
RFILE# NUMBER
STATUS VARCHAR2(7)
ENABLED VARCHAR2(10)
BYTES NUMBER
BLOCKS NUMBER
CREATE_BYTES NUMBER
BLOCK_SIZE NUMBER
NAME VARCHAR2(513)
SQL> col TABLESPACE_NAME for a20;
SQL> col FILE_NAME for a40;
SQL> select tablespace_name,file_name from dba_temp_files;
TABLESPACE_NAME FILE_NAME
-------------------- ----------------------------------------
TEMP /u01/oracle/oradata/orcl/temp01.dbf
TEMP1 /u01/oracle/oradata/orcl/temp1.dbf
建立临时表空间组：
SQL> create temporary tablespace temp2 tempfile '/u01/oracle/oradata/orcl/temp2.dbf' size 100m tablespace group temp11;
Tablespace created.
SQL> alter tablespace temp1 tablespace group temp11;
Tablespace altered.
查询临时表空间组：dba_tablespace_groups
SQL> desc dba_tablespace_groups
Name Null? Type
----------------------------------------- -------- ----------------------------
GROUP_NAME NOT NULL VARCHAR2(30)
TABLESPACE_NAME NOT NULL VARCHAR2(30)
SQL> select * from dba_tablespace_groups;
GROUP_NAME TABLESPACE_NAME
------------------------------ --------------------
TEMP11 TEMP1
TEMP11 TEMP2
临时表空间与临时表空间组区别：
A、temp group至少具备1个临时表空间
B、如果把表空间组下面的成员删除，就相当于把临时表空间组也删除了。
C、组名字和表空间名字不能有相同的。
临时表空间组好处：
A、sql语句进行并发操作时，使用临时表空间组有好处。
B、并发操作时，会话可以分配到不同的临时表空间里去。
C、可以随时添加临时表空间成员。
2、如何指定默认的临时表空间
数据库级别：
SQL> alter database default temporary tablespace temp11;
Database altered.
用户级别：
SQL>alter user scott temporary tablespace temp11;
Database altered.
3、备份：临时表空间不需要备份。
4、恢复：建立新的临时表空间，设置默认，删除旧的。或为临时表孔间加tempfile或启用临时表空间组。
物理结构和逻辑结构。
数据库的存储层次结构图：
.............逻辑结构： 物理结构：
......................
表空间类型：system、sysaux、temp、undo、index、其他
创建表空间：
语法：create tablespace <name>
datafile '<dir>' size N[k|m|g|t];
创建表空间时我们需呀考虑几个问题：
1）具有create tablespace权限
2）smallfile和bigfile（T级以上：可以减少数据问文件个数，方便管理）：如果系统默认是存放smallfile，则创建表空间create tablespace相当于cteate smallfile tablespace；如果系统默认是存放bigfile，则创建表空间create tablespace相当于cteate bigfile tablespace；
如何查看系统默认创建表空间是smallfile还是bigfile文件，可以通过查询database_properties来查看，如下：可知现系统默认创建为smallfile表空间文件。
SQL> desc database_properties
?? ????? ??
----------------------------------------- -------- ----------------------------
PROPERTY_NAME NOT NULL VARCHAR2(30)
PROPERTY_VALUE VARCHAR2(4000)
DESCRIPTION VARCHAR2(4000)
SQL> col PROPERTY_NAME for a10;
SQL> col PROPERTY_value for a20;
SQL> select PROPERTY_NAME,PROPERTY_VALUE from database_properties where property_name like '%TBS%';
PROPERTY_NAME PROPERTY_VALUE
------------------------------ --------------------
DEFAULT_TBS_TYPE SMALLFILE
如果想修改系统默认创建表空间为bigfile文件，操作如下：
SQL> alter database set default bigfile tablespace;
Database alterd.
SQL> select PROPERTY_NAME,PROPERTY_VALUE from database_properties where property_name like '%TBS%';
PROPERTY_NAME PROPERTY_VALUE
------------------------------ --------------------
DEFAULT_TBS_TYPE BIGFILE
3）IO是否够用。
表空间管理方式（区管理方式）：
1）字典管理：已淘汰：extent management dictionary
2）本地管理：9i后（默认）：extent management local
8i—>10g的数据迁移需要研究？
查看本地管理方式：dba_tablespace
SQL> select tablespace_name,EXTENT_MANAGEMENT from dba_tablespaces;
TABLESPACE_NAME EXTENT_MAN
------------------------------ ----------
SYSTEM LOCAL
UNDOTBS1 LOCAL
SYSAUX LOCAL
TEMP LOCAL
USERS LOCAL
表空间状态：1）offline、2）online、3）read only、4）read write
默认情况下表空间状态为online和read write：
SQL> select file#,status,enabled from v$datafile;
FILE# STATUS ENABLED
---------- ------- -------------------------------------------
1 SYSTEM READ WRITE
2 ONLINE READ WRITE
3 ONLINE READ WRITE
4 ONLINE READ WRITE
SQL> select b.tablespace_name,a.file#,a.status,a.enabled from v$datafile a,dba_data_files b where a.file#=b.file_id;
TABLESPACE_NAME FILE# STATUS ENABLED
------------------------------ ---------- ------- -----------------------------------------------------------------
SYSTEM 1 SYSTEM READ WRITE
UNDOTBS1 2 ONLINE READ WRITE
SYSAUX 3 ONLINE READ WRITE
USERS 4 ONLINE READ WRITE
修改表空间状态：
SQL> alter tablespace users read only;
SQL> alter tablespace users read write;
SQL> alter tablespace users offline;
???????
SQL> alter tablespace users online;
???????
| Tablespace | Online | Offline |
| System | 必须online | 必须read write |
| Sysaux | 可以offline | 不能read only |
| Undo | 不能offline | 不能read only |
system、sysaux不能改名
undo、temp表空间可以改名但是同时要把参数文件改了，不建议改。
users表空间可以改名
其他自定义表空间可以根据自己要求改名。
SQL> create tablespace fi datafile '/u01/oracle/oradata/orcl/fi.dbf' size 10m;
???????
SQL> alter tablespace fi rename to f1;
???????
表空间大小管理：
1）表空间自动扩张：
可以通过dba_data_files表的AUTOEXTENSIBLE字段查询表空间文件是否为自动扩张。
SQL> select tablespace_name,file_name,AUTOEXTENSIBLE from dba_data_files;
TABLESPACE FILE_NAME AUT
---------- -------------------------------------------------- ---
SYSTEM /u01/oracle/oradata/rezin/system01.dbf YES
UNDOTBS1 /u01/oracle/oradata/rezin/undotbs01.dbf YES
SYSAUX /u01/oracle/oradata/rezin/sysaux01.dbf YES
USERS /u01/oracle/oradata/rezin/users01.dbf YES
F1 /u01/oracle/oradata/orcl/fi.dbf NO
通过以上查询可知，只有F1表空间为非自动扩张状态，将其改为自动扩张表空间：
语法：SQL> alter database <路径>|<编号> autoextend on next nM maxsize Ng|t;
SQL> alter database datafile '/u01/oracle/oradata/orcl/fi.dbf' autoextend on;
SQL> select tablespace_name,file_name,AUTOEXTENSIBLE from dba_data_files;
TABLESPACE FILE_NAME AUT
---------- -------------------------------------------------- ---
SYSTEM /u01/oracle/oradata/rezin/system01.dbf YES
UNDOTBS1 /u01/oracle/oradata/rezin/undotbs01.dbf YES
SYSAUX /u01/oracle/oradata/rezin/sysaux01.dbf YES
USERS /u01/oracle/oradata/rezin/users01.dbf YES
F1 /u01/oracle/oradata/orcl/fi.dbf YES
2）手工resize数据文件大小
SQL> alter database datafile '/u01/oracle/oradata/orcl/fi.dbf' autoextend off;
SQL> alter database datafile '/u01/oracle/oradata/orcl/fi.dbf' resize 100m;
???????
3）添加数据文件（打开自动扩张）
SQL> alter tablespace f1 add datafile '/u01/oracle/oradata/orcl/f2.dbf' size 10m autoextend on next 10m maxsize 100m;
表空间数据文件的重命名和重定位：
条件：数据库在mount阶段或open阶段，归档模式，数据文件必须可以offline状态，如果数据文件不能offline，只能在mount状态重命名。
步骤：1）将要改名的表空间数据文件offline
2）操作系统级别移动数据文件（改名）
3）执行从命名命令
SQL> alter database rename file '<oldname>' to '<newname>';
4）将数据文件状态改为online状态。
SQL> alter tablespace f1 offline;
???????
SQL> ho cp /u01/oracle/oradata/orcl/f2.dbf /u01/oracle/oradata/orcl/f1.dbf
SQL> alter database rename file '/u01/oracle/oradata/orcl/f2.dbf'
to '/u01/oracle/oradata/orcl/f1.dbf';
???????
SQL> alter tablespace f1 online;
???????
删除表空间：
语法：drop tablespace <name> including contents and datafiles;
SQL> drop tablespace f1;
重新创建表空间：
SQL> create tablespace f2 datafile '/u01/oracle/oradata/orcl/f1.dbf' reuse;
???????
SQL> drop tablespace f2 including contents and datafiles;
???????
获取表空间和数据文件信息（数据文件相关视图）：
表空间信息：
dba_tablespace
v$tablespace
数据文件信息：
dba_data_files
v$datafile
临时数据文件信息：
dba_temp_files
v$tempfile
系统表空间：
字典所在，定义信息，一般不放用户数据1）空间管理：一般放单个文件最好,看磁盘空间是否够用等
2）备份：归档模式备份，非归档模式只能冷备。
热备：A)alter tablespace system begin backup;
B)$cp '<system dir>' /bak
C)alter tablespace system end backup;
rman备份：back tablespace system;
[oracle@localhost ~]$ rman target /
Recovery Manager: Release 10.2.0.1.0 - Production on Wed Mar 18 09:31:40 2015
Copyright (c) 1982, 2005, Oracle. All rights reserved.
connected to target database: REZIN (DBID=633392282)
RMAN> backup tablespace system;
3）system异常处理：
A非归档、无备份-->不能恢复
无法恢复
B归档、有备份、日志完整--->可以恢复
热备文件恢复：
SQL> startup
ORACLE instance started.
Total System Global Area 285212672 bytes
Fixed Size 1218968 bytes
Variable Size 96470632 bytes
Database Buffers 180355072 bytes
Redo Buffers 7168000 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 1 - see DBWR trace file
ORA-01110: data file 1: '/u01/oracle/oradata/orcl/system01.dbf'
SQL> ho ls /u01/oracle/oradata/orcl/system01.dbf
ls: /u01/oracle/oradata/orcl/system01.dbf: 没有那个文件或目录
SQL> alter database open;
alter database open
*
ERROR at line 1:
ORA-01113: file 1 needs media recovery
ORA-01110: data file 1: '/u01/oracle/oradata/orcl/system01.dbf'
SQL> recover database;
Media recovery complete.
SQL> alter database open;
Database altered.
rman恢复：
RMAN> list backup；
RMAN> restore tablespace system;
Starting restore at 19-MAR-15
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=155 devtype=DISK
channel ORA_DISK_1: starting datafile backupset restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to /u01/oracle/oradata/orcl/system01.dbf
channel ORA_DISK_1: reading from backup piece /u01/oracle/flash_recovery_area/ORCL/backupset/2015_03_19/o1_mf_nnndf_TAG20150319T175033_bjo6zc4b_.bkp
channel ORA_DISK_1: restored backup piece 1
piece handle=/u01/oracle/flash_recovery_area/ORCL/backupset/2015_03_19/o1_mf_nnndf_TAG20150319T175033_bjo6zc4b_.bkp tag=TAG20150319T175033
channel ORA_DISK_1: restore complete, elapsed time: 00:00:35
Finished restore at 19-MAR-15
RMAN> recover tablespace system;
Starting recover at 19-MAR-15
using channel ORA_DISK_1
starting media recovery
media recovery complete, elapsed time: 00:00:05
Finished recover at 19-MAR-15
RMAN> sql 'alter database open';
sql statement: alter database open
RMAN>
C归档、有备份、日志不完整--->可以恢复，但不保证数据丢失
4、system表空间不能offline，不能read only，不能改名
sysaux表空间
作用：存储一些默认的工具，程序,减轻system负担，尤其IO负担。sysaux表空间名字不能更改，不能drop，不能read only，能够offline
查询sysaux表空间下有哪些工具：
SQL> desc v$sysaux_occupants
Name Null? Type
----------------------------------------- -------- ----------------------------
OCCUPANT_NAME VARCHAR2(64)
OCCUPANT_DESC VARCHAR2(64)
SCHEMA_NAME VARCHAR2(64)
MOVE_PROCEDURE VARCHAR2(64)
MOVE_PROCEDURE_DESC VARCHAR2(64)
SPACE_USAGE_KBYTES NUMBER
SQL> col OCCUPANT_NAME for a20;
SQL> col SCHEMA_NAME for a20;
SQL> select OCCUPANT_NAME, SCHEMA_NAME from v$sysaux_occupants;
OCCUPANT_NAME SCHEMA_NAME
-------------------- --------------------
LOGMNR SYSTEM
LOGSTDBY SYSTEM
STREAMS SYS
XDB XDB
AO SYS
XSOQHIST SYS
XSAMD OLAPSYS
SM/AWR SYS
SM/ADVISOR SYS
SM/OPTSTAT SYS
SM/OTHER SYS
STATSPACK PERFSTAT
ODM DMSYS
SDO MDSYS
WM WMSYS
ORDIM ORDSYS
ORDIM/PLUGINS ORDPLUGINS
ORDIM/SQLMM SI_INFORMTN_SCHEMA
EM SYSMAN
TEXT CTXSYS
ULTRASEARCH WKSYS
ULTRASEARCH_DEMO_USE WK_TEST
EXPRESSION_FILTER EXFSYS
EM_MONITORING_USER DBSNMP
TSM TSMSYS
JOB_SCHEDULER SYS
26 rows selected.
备份：归档（非归档只能冷备，无大意义）可以热备也可以rman备份。
热备：A)alter tablespace sysaux begin backup;
B)$cp '<system dir>' /bak
C)alter tablespace sysaux end backup;
rman备份：back tablespace sysaux;
[oracle@localhost ~]$ rman target /
Recovery Manager: Release 10.2.0.1.0 - Production on Wed Mar 18 09:31:40 2015
Copyright (c) 1982, 2005, Oracle. All rights reserved.
connected to target database: REZIN (DBID=633392282)
RMAN> back tablespace sysaux;
sysaux表空间的异常处理：
1）有备份--->还原，恢复
使用热备文件恢复：
SQL> startup
ORACLE instance started.
Total System Global Area 285212672 bytes
Fixed Size 1218968 bytes
Variable Size 79693416 bytes
Database Buffers 197132288 bytes
Redo Buffers 7168000 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 3 - see DBWR trace file
ORA-01110: data file 3: '/u01/oracle/oradata/orcl/sysaux01.dbf'
SQL> ho cp /u01/oracle/sysaux01.dbf /u01/oracle/oradata/orcl/sysaux01.dbf
SQL> alter database open;
alter database open
*
ERROR at line 1:
ORA-01113: file 3 needs media recovery
ORA-01110: data file 3: '/u01/oracle/oradata/orcl/sysaux01.dbf'
SQL> recover database;
Media recovery complete.
SQL> alter database open;
Database altered.
rman备份恢复：
[oracle@localhost ~]$ rman target /
RMAN> list backup;
RMAN> restore tablespace sysaux;
Starting restore at 20-MAR-15
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=155 devtype=DISK
channel ORA_DISK_1: starting datafile backupset restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
restoring datafile 00003 to /u01/oracle/oradata/orcl/sysaux01.dbf
channel ORA_DISK_1: reading from backup piece /u01/oracle/flash_recovery_area/ORCL/backupset/2015_03_20/o1_mf_nnndf_TAG20150320T054421_bjpjsot8_.bkp
channel ORA_DISK_1: restored backup piece 1
piece handle=/u01/oracle/flash_recovery_area/ORCL/backupset/2015_03_20/o1_mf_nnndf_TAG20150320T054421_bjpjsot8_.bkp tag=TAG20150320T054421
channel ORA_DISK_1: restore complete, elapsed time: 00:00:16
Finished restore at 20-MAR-15
RMAN> recover tablespace sysaux;
Starting recover at 20-MAR-15
using channel ORA_DISK_1
starting media recovery
media recovery complete, elapsed time: 00:00:02
Finished recover at 20-MAR-15
RMAN> sql 'alter database open';
sql statement: alter database open
RMAN>
2）无备份--->offline sysaux表空间，然后迁移数据，再重新建库，将数据迁移回来。
无备份下sysaux表空间损坏如何打开数据库：
undo表空间管理：
undo表空间作用：回滚（没有提交），前滚（已提交，但没有写入数据文件）1）事务的回退：rollback
2）事务的恢复：撤销没有提交的内容
3）读一致性：事务只能查询自己修改过的内容或是原来的内容（锁的作用）。
4）闪回数据：查询3600面之前的数据
undo表空间管理模式/undo表空间参数：自动/手动，由undo_management参数决定undo表空间管理模式。
查询undo表空间管理模式：
SQL> show parameter undo_m
NAME TYPE VALUE
------------------------------------ ---------- -----------------------------------------------------
undo_management string AUTO
查询系统使用的默认undo表空间：
SQL> show parameter undo_t
NAME TYPE VALUE
------------------------------------ ---------- ------------------------------
undo_tablespace string UNDOTBS1
undo表空间段类型：
1）系统段：存放系统表空间产生的镜像数据。
2）非系统段：存放非系统表空间产生的镜像数据。
3）临时段：能够offline的表空间产生，记录offline阶段oracle数据库产生的数据。
查询如下视图：查寻系统段和非系统段通过v$rollname
SQL> select * from v$rollname;
USN NAME
---------- --------------------------
0 SYSTEM
1 _SYSSMU1$
2 _SYSSMU2$
3 _SYSSMU3$
4 _SYSSMU4$
5 _SYSSMU5$
6 _SYSSMU6$
7 _SYSSMU7$
8 _SYSSMU8$
9 _SYSSMU9$
10 _SYSSMU10$
11 rows selected.
查询临时段通过dba_segments：
SQL> ALTER tablespace users offline;
Tablespace altered.
SQL> col SEGMENT_NAME for a20;
SQL> col SEGMENT_TYPE for a20;
SQL> select segment_name,segment_type from dba_segments where segment_type like '%DEF%';
SEGMENT_NAME SEGMENT_TYPE
-------------------- --------------------
1.60881 DEFERRED ROLLBACK
查询undo表空间保存历史数据最久多少：
SQL> show parameter undo_r
NAME TYPE VALUE
------------------------------------ ---------- ------------------------------
undo_retention integer 900
undo表空间建立、删除、更改：
1）建立：建库时自动建立
手工建立：SQL>create smallfile|bigfile undo tablespace <name> datafile <dir> size <size> autoextend on next size <size> maxsize <size>;
SQL> create undo tablespace undo1 datafile '/u01/oracle/oradata/orcl/undo1.dbf' size 100m autoextend on;
Tablespace created.
2）删除：drop tablespace <undoname> including contents and datafile;
3）更改：alter system set audo_tablespace=<undo_name>;
OR
SQL>alter tablespace undotbs1 tename to undotbs;
SQL>shutdown immediate
SQL>startup
估算undo表空间该设为多大大小：
公式：undo space=(undo_retention*(undo blocks per second*db block size))+db block_size
SQL> show parameter undo_retention
NAME TYPE VALUE
------------------------------------ ---------- ------------------------------
undo_retention integer 900
SQL> select sum(undoblks)/sum((end_time-begin_time)*10800) from v$undostat;
SUM(UNDOBLKS)/SUM((END_TIME-BEGIN_TIME)*10800)
----------------------------------------------
1.98037077
SQL> select 900* 1.98037077*8192 from dual;
900*1.98037077*8192
-----------------------------------------
14600877.6
查询undo表空间当前分配大小：
1）SQL> select max(block_id) from dba_extents where file_id=2;
MAX(BLOCK_ID)
-------------
4617
2）SQL> select 4617*8192/1024/1024||'G' from dual;
4617*8192/1
-----------------------------
36.0703125G
作用：可以将undo表空间容量变小。
undo的资料查询：（47后半部分）
1）SQL> desc dba_rollback_segs
Name Null? Type
----------------------------------------- -------- ----------------------------
SEGMENT_NAME NOT NULL VARCHAR2(30)
OWNER VARCHAR2(6)
TABLESPACE_NAME NOT NULL VARCHAR2(30)
SEGMENT_ID NOT NULL NUMBER
FILE_ID NOT NULL NUMBER
BLOCK_ID NOT NULL NUMBER
INITIAL_EXTENT NUMBER
NEXT_EXTENT NUMBER
MIN_EXTENTS NOT NULL NUMBER
MAX_EXTENTS NOT NULL NUMBER
PCT_INCREASE NUMBER
STATUS VARCHAR2(16)
INSTANCE_NUM VARCHAR2(40)
RELATIVE_FNO NOT NULL NUMBER
SQL> select TABLESPACE_NAME,SEGMENT_NAME,FILE_ID from dba_rollback_segs;
2）SQL> desc v$rollname
Name Null? Type
----------------------------------------- -------- ----------------------------
USN NUMBER
NAME NOT NULL VARCHAR2(30)
SQL> select * from v$rollname;
USN NAME
---------- ----------
0 SYSTEM
1 _SYSSMU1$
2 _SYSSMU2$
3 _SYSSMU3$
4 _SYSSMU4$
5 _SYSSMU5$
6 _SYSSMU6$
7 _SYSSMU7$
8 _SYSSMU8$
9 _SYSSMU9$
10 _SYSSMU10$
11 rows selected.
3）SQL> desc v$rollstat;
Name Null? Type
----------------------------------------- -------- ----------------------------
USN NUMBER
LATCH NUMBER
EXTENTS NUMBER
RSSIZE NUMBER
WRITES NUMBER
XACTS NUMBER
GETS NUMBER
WAITS NUMBER
OPTSIZE NUMBER
HWMSIZE NUMBER
SHRINKS NUMBER
WRAPS NUMBER
EXTENDS NUMBER
AVESHRINK NUMBER
AVEACTIVE NUMBER
STATUS VARCHAR2(15)
CUREXT NUMBER
CURBLK NUMBER
4）SQL> desc dba_segments
Name Null? Type
----------------------------------------- -------- ----------------------------
OWNER VARCHAR2(30)
SEGMENT_NAME VARCHAR2(81)
PARTITION_NAME VARCHAR2(30)
SEGMENT_TYPE VARCHAR2(18)
TABLESPACE_NAME VARCHAR2(30)
HEADER_FILE NUMBER
HEADER_BLOCK NUMBER
BYTES NUMBER
BLOCKS NUMBER
EXTENTS NUMBER
INITIAL_EXTENT NUMBER
NEXT_EXTENT NUMBER
MIN_EXTENTS NUMBER
MAX_EXTENTS NUMBER
PCT_INCREASE NUMBER
FREELISTS NUMBER
FREELIST_GROUPS NUMBER
RELATIVE_FNO NUMBER
BUFFER_POOL VARCHAR2(7)
5）SQL> desc v$transaction
Name Null? Type
----------------------------------------- -------- ----------------------------
ADDR RAW(4)
XIDUSN NUMBER
XIDSLOT NUMBER
XIDSQN NUMBER
UBAFIL NUMBER
UBABLK NUMBER
UBASQN NUMBER
UBAREC NUMBER
STATUS VARCHAR2(16)
START_TIME VARCHAR2(20)
START_SCNB NUMBER
START_SCNW NUMBER
START_UEXT NUMBER
START_UBAFIL NUMBER
START_UBABLK NUMBER
START_UBASQN NUMBER
START_UBAREC NUMBER
SES_ADDR RAW(4)
FLAG NUMBER
SPACE VARCHAR2(3)
RECURSIVE VARCHAR2(3)
NOUNDO VARCHAR2(3)
PTX VARCHAR2(3)
NAME VARCHAR2(256)
PRV_XIDUSN NUMBER
PRV_XIDSLT NUMBER
PRV_XIDSQN NUMBER
PTX_XIDUSN NUMBER
PTX_XIDSLT NUMBER
PTX_XIDSQN NUMBER
DSCN-B NUMBER
DSCN-W NUMBER
USED_UBLK NUMBER
USED_UREC NUMBER
LOG_IO NUMBER
PHY_IO NUMBER
CR_GET NUMBER
CR_CHANGE NUMBER
START_DATE DATE
DSCN_BASE NUMBER
DSCN_WRAP NUMBER
START_SCN NUMBER
DEPENDENT_SCN NUMBER
XID RAW(8)
PRV_XID RAW(8)
PTX_XID RAW(8)
undo表空间的应用：
1）事务的回退：事务没有结束之前才能执行。
SQL>rollback;
SQL> show user
USER is "SCOTT"
SQL> delete from emp where deptno=10;
3 rows deleted
SQL> savepoint s1;
Savepoint created.
SQL> delete from emp where deptno=20;
5 rows deleted.
SQL> savepoint s2;
Savepoint created.
SQL> delete from emp where deptno=30;
6 rows deleted.
SQL> savepoint s3;
Savepoint created.
SQL> select * from emp;
no rows selected
SQL> rollback to s2;
Rollback complete.
SQL> select * from emp;
EMPNO ENAME JOB MGR HIREDATE SAL COMM
---------- ---------- --------- ---------- --------- ---------- ----------
DEPTNO
----------
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300
30
7521 WARD SALESMAN 7698 22-FEB-81 1250 500
30
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400
30
7698 BLAKE MANAGER 7839 01-MAY-81 2850
30
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0
30
7900 JAMES CLERK 7698 03-DEC-81 950
30
6 rows selected.
SQL> rollback to s1;
Rollback complete.
SQL> select * from emp;
EMPNO ENAME JOB MGR HIREDATE SAL COMM
---------- ---------- --------- ---------- --------- ---------- ----------
DEPTNO
----------
7369 SMITH CLERK 7902 17-DEC-80 800
20
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300
30
7521 WARD SALESMAN 7698 22-FEB-81 1250 500
30
7566 JONES MANAGER 7839 02-APR-81 2975
20
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400
30
7698 BLAKE MANAGER 7839 01-MAY-81 2850
30
7788 SCOTT ANALYST 7566 19-APR-87 3000
20
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0
30
7876 ADAMS CLERK 7788 23-MAY-87 1100
20
7900 JAMES CLERK 7698 03-DEC-81 950
30
7902 FORD ANALYST 7566 03-DEC-81 3000
20
11 rows selected.
2）事务的提交：自动或手工结束事务。
commit或是执行ddl语句或者设置数据库自动提交。
SQL> commit;
Commit complete.
3）闪回数据：
SQL> insert into emp select * from emp as of timestamp sysdate-5/1440;
14 rows created.
undo备份：
热备：A)alter tablespace undotbs1 begin backup;
B)$cp '<undotbs1 dir>' /bak
C)alter tablespace undotbs1 end backup;
rman备份：
rman备份：back tablespace undotbs1;
[oracle@localhost ~]$ rman target /
Recovery Manager: Release 10.2.0.1.0 - Production on Wed Mar 18 09:31:40 2015
Copyright (c) 1982, 2005, Oracle. All rights reserved.
connected to target database: REZIN (DBID=633392282)
RMAN> back tablespace undotbs1;
恢复：
[oracle@localhost ~]$ rman target /
Recovery Manager: Release 10.2.0.1.0 - Production on Sat Mar 21 00:28:34 2015
Copyright (c) 1982, 2005, Oracle. All rights reserved.
connected to target database: ORCL (DBID=1402521782, not open)
RMAN> restore tablespace undotbs1;
Starting restore at 21-MAR-15
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=156 devtype=DISK
channel ORA_DISK_1: starting datafile backupset restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
restoring datafile 00002 to /u01/oracle/oradata/orcl/undotbs01.dbf
channel ORA_DISK_1: reading from backup piece /u01/oracle/flash_recovery_area/ORCL/backupset/2015_03_21/o1_mf_nnndf_TAG20150321T002210_bjrl9mqr_.bkp
channel ORA_DISK_1: restored backup piece 1
piece handle=/u01/oracle/flash_recovery_area/ORCL/backupset/2015_03_21/o1_mf_nnndf_TAG20150321T002210_bjrl9mqr_.bkp tag=TAG20150321T002210
channel ORA_DISK_1: restore complete, elapsed time: 00:00:07
Finished restore at 21-MAR-15
RMAN> recover tablespace undotbs1;
Starting recover at 21-MAR-15
using channel ORA_DISK_1
starting media recovery
media recovery complete, elapsed time: 00:00:02
Finished recover at 21-MAR-15
SQL> alter database datafile 2 online;
Database altered.
SQL> alter database open;
Database altered.
无备份情况下的恢复：（48集）
1）系统中是否存在其他的undo表空间，如果存在，则替换其他的undo表空间，并且将损坏的undo表空间脱机，然后启动数据库到open阶段，再删除损坏的undo表空间，然后建立新的undo表空间。
2）系统中没有其他的undo表空间，使用隐藏参数，让undo表空间offline，打开数据库，再删除损坏undo表空间，然后再建立新的undo表空间。
无备份情况下的恢复步骤：
附：dml语句执行过程图解：
users表空间管理
作用：默认的用户表空间，存放用户数据。如何指定用户的默认表空间：
查询用户默认用户表空间：database_properties
SQL> select PROPERTY_NAME,PROPERTY_VALUE from database_properties where property_name like '%DEF%';
PROPERTY_NAME PROPERTY_VALUE
----------------------------------- ------------------------------
DEFAULT_TEMP_TABLESPACE TEMP
DEFAULT_PERMANENT_TABLESPACE USERS
DEFAULT_TBS_TYPE SMALLFILE
修改用户默认表空间：
SQL> alter database default tablespace users1;
Database altered.
结果如下：
SQL> select PROPERTY_NAME,PROPERTY_VALUE from database_properties where property_name like '%DEF%';
PROPERTY_NAME PROPERTY_VALUE
----------------------------------- ------------------------------
DEFAULT_TEMP_TABLESPACE TEMP
DEFAULT_PERMANENT_TABLESPACE USERS1
DEFAULT_TBS_TYPE SMALLFILE
users表空间备份：包括用户自定义的表孔间备份方法
热备：A)alter tablespace users begin backup;
B)$cp '<system dir>' /bak
C)alter tablespace users end backup;
rman备份：back tablespace users;
[oracle@localhost ~]$ rman target /
Recovery Manager: Release 10.2.0.1.0 - Production on Wed Mar 18 09:31:40 2015
Copyright (c) 1982, 2005, Oracle. All rights reserved.
connected to target database: REZIN (DBID=633392282)
RMAN> back tablespace users;
users表空间恢复：包括用户自定义的表孔间还原方法
1）热备还原：
SQL> ho cp /u01/oracle/users01.dbf /u01/oracle/oradata/orcl/users01.dbf
SQL> recover tablespace users;
Media recovery complete.
SQL> alter database open;
Database altered.
2）rman还原
RMAN>restore tablespace users;
RMAN>recover tablespace users;
SQL>alter tablespace users online;
3）用户自定义表空间，无备份，归档模式下，表空间创建以来日志文件全恢复方法：
alter database create datafile N as '<dir>';
SQL> alter tablespace users1 offline;
alter tablespace users1 offline
*
ERROR at line 1:
ORA-01116: error in opening database file 6
ORA-01110: data file 6: '/u01/oracle/oradata/orcl/user1.dbf'
ORA-27041: unable to open file
Linux Error: 2: No such file or directory
Additional information: 3
SQL> alter database datafile 6 offline;
Database altered.
SQL> alter database create datafile 6 as '/u01/oracle/oradata/orcl/user1.dbf';
Database altered.
SQL> recover tablespace users1;
Media recovery complete.
SQL> alter tablespace users1 online;
Tablespace altered.
SQL> select * from u1.u;
I
----------
1
1
1
附加：如果以上办法还是不能恢复users1表空间，则表示该表空间不能恢复，我们只能舍弃该表空间中的数据：即脱机数据文件。
SQL>alter database datafile <name> offline;
temp表空间管理：
作用：用于存放用户排序的临时数据。排序首先进行内存排序，如果内存中排序满足不了就会采取temp表空间进行排序。如何指定用户的默认临时表空间：
查询用户默认用户表空间：database_properties
SQL> select PROPERTY_NAME,PROPERTY_VALUE from database_properties where property_name like '%DEF%';
PROPERTY_NAME PROPERTY_VALUE
----------------------------------- ------------------------------
DEFAULT_TEMP_TABLESPACE TEMP
DEFAULT_PERMANENT_TABLESPACE USERS
DEFAULT_TBS_TYPE SMALLFILE
修改用户默认表空间：
SQL> alter database default temporary tablespace temp1;
Database altered.
结果如下：
SQL> select PROPERTY_NAME,PROPERTY_VALUE from database_properties where property_name like '%DEF%';
PROPERTY_NAME PROPERTY_VALUE
----------------------------------- ------------------------------
DEFAULT_TEMP_TABLESPACE TEMP1
DEFAULT_PERMANENT_TABLESPACE USERS
DEFAULT_TBS_TYPE SMALLFILE
1建立temp表空间
SQL> create temporary tablespace temp1 tempfile '/u01/oracle/oradata/orcl/temp1.dbf' size 100m;
Tablespace created.
查询系统下的临时表空间：desc dba_temp_files、v$tempfile
SQL> desc dba_temp_files
Name Null? Type
----------------------------------------- -------- ----------------------------
FILE_NAME VARCHAR2(513)
FILE_ID NUMBER
TABLESPACE_NAME NOT NULL VARCHAR2(30)
BYTES NUMBER
BLOCKS NUMBER
STATUS CHAR(9)
RELATIVE_FNO NUMBER
AUTOEXTENSIBLE VARCHAR2(3)
MAXBYTES NUMBER
MAXBLOCKS NUMBER
INCREMENT_BY NUMBER
USER_BYTES NUMBER
USER_BLOCKS NUMBER
SQL> desc v$tempfile
Name Null? Type
----------------------------------------- -------- ----------------------------
FILE# NUMBER
CREATION_CHANGE# NUMBER
CREATION_TIME DATE
TS# NUMBER
RFILE# NUMBER
STATUS VARCHAR2(7)
ENABLED VARCHAR2(10)
BYTES NUMBER
BLOCKS NUMBER
CREATE_BYTES NUMBER
BLOCK_SIZE NUMBER
NAME VARCHAR2(513)
SQL> col TABLESPACE_NAME for a20;
SQL> col FILE_NAME for a40;
SQL> select tablespace_name,file_name from dba_temp_files;
TABLESPACE_NAME FILE_NAME
-------------------- ----------------------------------------
TEMP /u01/oracle/oradata/orcl/temp01.dbf
TEMP1 /u01/oracle/oradata/orcl/temp1.dbf
建立临时表空间组：
SQL> create temporary tablespace temp2 tempfile '/u01/oracle/oradata/orcl/temp2.dbf' size 100m tablespace group temp11;
Tablespace created.
SQL> alter tablespace temp1 tablespace group temp11;
Tablespace altered.
查询临时表空间组：dba_tablespace_groups
SQL> desc dba_tablespace_groups
Name Null? Type
----------------------------------------- -------- ----------------------------
GROUP_NAME NOT NULL VARCHAR2(30)
TABLESPACE_NAME NOT NULL VARCHAR2(30)
SQL> select * from dba_tablespace_groups;
GROUP_NAME TABLESPACE_NAME
------------------------------ --------------------
TEMP11 TEMP1
TEMP11 TEMP2
临时表空间与临时表空间组区别：
A、temp group至少具备1个临时表空间
B、如果把表空间组下面的成员删除，就相当于把临时表空间组也删除了。
C、组名字和表空间名字不能有相同的。
临时表空间组好处：
A、sql语句进行并发操作时，使用临时表空间组有好处。
B、并发操作时，会话可以分配到不同的临时表空间里去。
C、可以随时添加临时表空间成员。
2、如何指定默认的临时表空间
数据库级别：
SQL> alter database default temporary tablespace temp11;
Database altered.
用户级别：
SQL>alter user scott temporary tablespace temp11;
Database altered.
3、备份：临时表空间不需要备份。
4、恢复：建立新的临时表空间，设置默认，删除旧的。或为临时表孔间加tempfile或启用临时表空间组。
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