作者y18511664518·2017-08-04 18:10

技术总监·长城超云

oracle数据库知识点分享专题二----逻辑备份

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一	 知识点简介 
逻辑备份的方式有好几种，在这里我们简单的介绍一下导入导出，以方便大家在日常的测试和准生产环境使用。

二	 知识点内容
导出(exp) & 导入(imp) 
	利用Export可将数据从数据库中提取出来，就是将select的结果存到一个FS二进制文件上
	利用Import则可将提取出来的数据送回到Oracle数据库中去。 
	要读写数据文件内数据,所以数据库必须open
	不能备份活跃频繁数据 
	exp满足select的所有特性 比如权限或读一致性
	imp满足insert的所有特性 比如主键或空间不足

Oracle支持三种方式基本类型的输出： 
1.表方式（T方式），将指定表的数据导出。 
2.用户方式（U方式），将指定用户的所有对象及数据导出。 
3.全库方式（Full方式），数据库中的所有对象导出。

数据导入（Import）的过程是数据导出（Export）的逆过程，分别将数据文件导入数据库和将数据库数据导出到数据文件。

三	 实验过程

1.	交互模式导出exp表

[oracle@dba ~]$ exp
Export: Release 10.2.0.1.0 - Production on Mon Apr 4 16:58:41 2011
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
Username: scott
Password: 
Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
Enter array fetch buffer size: 4096 >

Export file: expdat.dmp > scott_tab_emp.dmp  
(2)U(sers), or (3)T(ables): (2)U > T

Export table data (yes/no): yes >

Compress extents (yes/no): yes >

Export done in AL32UTF8 character set and AL16UTF16 NCHAR character set

About to export specified tables via Conventional Path ...

Table(T) or Partition(T:P) to be exported: (RETURN to quit) > emp

. . exporting table                            EMP         14 rows exported

Table(T) or Partition(T:P) to be exported: (RETURN to quit) > dept

. . exporting table                           DEPT          4 rows exported

Table(T) or Partition(T:P) to be exported: (RETURN to quit) >  回车退出

Export terminated successfully with warnings.
[oracle@dba ~]$

查看备份文件
[oracle@dba ~]$ ll -thr scott_tab_emp.dmp 
-rw-r--r-- 1 oracle oinstall 24K 04-04 17:00 scott_tab_emp.dmp
[oracle@dba ~]$ file scott_tab_emp.dmp 
scott_tab_emp.dmp: DBase 3 data file (1380929624 records)
[oracle@dba ~]$ strings scott_tab_emp.dmp

导出的文件是二进制文件 如果要经历FTP传输 一定要使用binary传输模式传 如果使用ASCII模式传输会损坏文件
	windows cmd里的ftp 默认是ascii传输模式

linux   lftp ftp等工具默认基本都是binary模式
	修改方法

C:\\>ftp
	ftp> status
	Not connected.
	Type: ascii; Verbose: On ; Bell: Off ; Prompting: On ; Globbing: On
	Debugging: Off ; Hash mark printing: Off .
	ftp>
	ftp> help
	Commands may be abbreviated.

!               delete
	?               debug
	append          dir
	ascii           disconnect
	bell            get
	binary          glob
	bye             hash
	cd              help
	close           lcd
	ftp>

[oracle@dba ~]$ ftp 127.0.0.1
	Connected to 127.0.0.1 (127.0.0.1).
	220 (vsFTPd 2.0.5)
	Name (127.0.0.1:oracle): 
	331 Please specify the password.
	Password:
	230 Login successful.
	Remote system type is UNIX.
	Using binary mode to transfer files.
	ftp> status
	Connected to 127.0.0.1.
	No proxy connection.
	Mode: stream; Type: binary; Form: non-print; Structure: file
	Verbose: on; Bell: off; Prompting: on; Globbing: on
	Store unique: off; Receive unique: off
	Case: off; CR stripping: on
	Ntrans: off
	Nmap: off
	Hash mark printing: off; Use of PORT cmds: on
	Tick counter printing: off
	ftp>

[oracle@dba ~]$ lftp oracle@127.0.0.1
	口令: 
	lftp oracle@127.0.0.1:~> help get
	用法: get [OPTS] <rfile> [-o <lfile>]
	Retrieve remote file <rfile> and store it to local file <lfile>.
	.........
	 -a  use ascii mode (binary is the default)
	.........
	lftp oracle@127.0.0.1:~> help put
	用法: put [OPTS] <lfile> [-o <rfile>]
	Upload <lfile> with remote name <rfile>.
	.........
	 -a  use ascii mode (binary is the default)
	.........
	lftp oracle@127.0.0.1:~>

备份出来的是什么内容  只是对象的元数据 + 用户数据
[oracle@dba exp_dir]$ strings cmd_scott_tab.dmp | grep -i 'CREATE' --color
CREATE TABLE "EMP" ("EMPNO" NUMBER(4, 0), "ENAME" VARCHAR2(10), ....
CREATE UNIQUE INDEX "PK_EMP" ON "EMP" ("EMPNO" )  ....
CREATE TABLE "DEPT" ("DEPTNO" NUMBER(2, 0), "DNAME" VARCHAR2(14), ....
CREATE UNIQUE INDEX "PK_DEPT" ON "DEPT" ("DEPTNO" )  ....

2.	命令模式备份表

[oracle@dba exp_dir]$ exp USERID=SCOTT/seker TABLES=EMP,DEPT FILE=cmd_scott_tab.dmp

Export: Release 10.2.0.1.0 - Production on Mon Apr 4 17:16:22 2011

About to export specified tables via Conventional Path ...
. . exporting table                            EMP         14 rows exported
. . exporting table                           DEPT          4 rows exported
Export terminated successfully without warnings.
[oracle@dba exp_dir]$

3.	交互模式备份schema
	
[oracle@dba exp_dir]$ exp

Export: Release 10.2.0.1.0 - Production on Mon Apr 4 17:37:00 2011

Username: scott
Password:

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
Enter array fetch buffer size: 4096 >

Export file: expdat.dmp > schema_scott.dmp

(2)U(sers), or (3)T(ables): (2)U > U

Export grants (yes/no): yes >

Export table data (yes/no): yes >

Compress extents (yes/no): yes >

Export done in AL32UTF8 character set and AL16UTF16 NCHAR character set
...............
Export terminated successfully without warnings.
[oracle@dba exp_dir]$

4.	命令模式备份schema
[oracle@dba exp_dir]$ exp userid=scott/seker file=schema.scott.dmp

.............
Export terminated successfully without warnings.
[oracle@dba exp_dir]$

5.	只导出部分数据

[oracle@dba exp_dir]$ exp userid=scott/seker tables=emp query=\\'where deptno=10\\' statistics=none file=./emp_deptno_10.dmp log=./emp_deptno_10.log
表上有统计信息的时候会报EXP-0091错误，添加statistics=none即可
Export: Release 10.2.0.1.0 - Production on Mon Apr 4 17:59:29 2011

About to export specified tables via Conventional Path ...
. . exporting table                            EMP
.
                                                            3 rows exported
Export terminated successfully without warnings.
[oracle@dba exp_dir]$

6.	只导出表结构
	导出时一定要加COMPRESS=n的选项 否则导入表是原始表的高水位 且没数据
	一个表大小是5M 
	COMPRESS=n 时得到元数据: STORAGE(INITIAL 65536)
	COMPRESS=y(默认) 时得到元数据:STORAGE(INITIAL 5242880) 这样创建的表很大 又没数据
[oracle@dba ~]$ exp scott/seker tables=ob rows=n file=./ob.dmp

[oracle@dba ~]$ exp scott/seker tables=ob rows=n COMPRESS=n file=./ob2.dmp

SQL> select segment_name,sum(bytes)/1024/1024 from user_extents where segment_name='OB' group by segment_name;

SEGMENT_NAME		  SUM(BYTES)/1024/1024
------------------------- --------------------
OB					     5

SQL> drop table OB PURGE;

Table dropped.

SQL> !
[oracle@dba ~]$ ls
Desktop  ob2.dmp  ob.dmp
[oracle@dba ~]$ imp userid=scott/seker file=ob.dmp 
[oracle@dba ~]$ exit
SQL> select segment_name,sum(bytes)/1024/1024 from user_extents where segment_name='OB' group by segment_name;

SEGMENT_NAME		  SUM(BYTES)/1024/1024
------------------------- --------------------
OB					     5

SQL> !
[oracle@dba ~]$ exit
exit

SQL> drop table ob purge;

Table dropped.

SQL> !
[oracle@dba ~]$ imp userid=scott/seker file=ob2.dmp

SQL> select segment_name,sum(bytes)/1024/1024 from user_extents where segment_name='OB' group by segment_name;

SEGMENT_NAME		  SUM(BYTES)/1024/1024
------------------------- --------------------
OB					 .0625

SQL>

7.	使用参数文件

[oracle@dba exp_dir]$ cat exp.txt 
userid=scott/seker
tables=emp
query='where deptno=10'
statistics=none
file=./emp_deptno_10.dmp
buffer=100000
feedback=2
log=./emp_deptno_10.log
[oracle@dba exp_dir]$ exp PARFILE=exp.txt

Export: Release 10.2.0.1.0 - Production on Mon Apr 4 17:59:52 2011

当query中带有单引号时 用两个引号代替
[oracle@dba exp_dir]$ cat exp.txt 
userid=scott/seker
tables=emp
query='where deptno=10 and ename=''KING'''
statistics=none
file=./emp_deptno_10.dmp
buffer=100000
feedback=2
log=./emp_deptno_10.log
[oracle@dba exp_dir]$

8.	闪回导出（导出历史上某一时间点的数据状态，依赖undo老镜像）:
--/home/oracle/exp.txt--
userid=system/oracle
tables=scott.emp
file=/home/oracle/expdept.dmp 
flashback_time="to_timestamp('2011-03-28 15:25:06','yyyy-mm-dd hh24:mi:ss')"
buffer=100000 
feedback=5000 
log=/home/oracle/expdept.log

9.	备份的常用参数
	FEEDBACK             display progress every x rows (0)
	FILESIZE             maximum size of each dump file
	INDEXES		     export indexes (Y)
	TRIGGERS     	     export triggers (Y)
	LOG        	     log file of screen output

10.	导入imp

指定表导入
[oracle@dba exp_dir]$ imp userid=scott/seker file=schema.scott.dmp tables=t1 ;

Import: Release 10.2.0.1.0 - Production on Mon Apr 4 18:36:26 2011

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

Export file created by EXPORT:V10.02.01 via conventional path
import done in AL32UTF8 character set and AL16UTF16 NCHAR character set
. importing SCOTT's objects into SCOTT
. importing SCOTT's objects into SCOTT
. . importing table                           "T1"      24672 rows imported
Import terminated successfully without warnings.
[oracle@dba exp_dir]$

11.	导入带有外键约束的表

要连同主键表一起带入 否则建立外键报错 带有trigger的级联表也要这样
[oracle@dba exp_dir]$ imp userid=scott/seker file=schema.scott.dmp tables=emp ;

Import: Release 10.2.0.1.0 - Production on Mon Apr 4 18:36:59 2011

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

Export file created by EXPORT:V10.02.01 via conventional path
import done in AL32UTF8 character set and AL16UTF16 NCHAR character set
. importing SCOTT's objects into SCOTT
. importing SCOTT's objects into SCOTT
. . importing table                          "EMP"         14 rows imported
IMP-00017: following statement failed with ORACLE error 942:
 "ALTER TABLE "EMP" ADD CONSTRAINT "FK_DEPTNO" FOREIGN KEY ("DEPTNO") REFEREN"
 "CES "DEPT" ("DEPTNO") ENABLE NOVALIDATE"
IMP-00003: ORACLE error 942 encountered
ORA-00942: table or view does not exist
About to enable constraints...
IMP-00017: following statement failed with ORACLE error 2430:
 "ALTER TABLE "EMP" ENABLE CONSTRAINT "FK_DEPTNO""
Import terminated successfully with warnings.
[oracle@dba exp_dir]$

SQL> drop table emp purge;

Table dropped.

SQL>

[oracle@dba exp_dir]$ imp userid=scott/seker file=schema.scott.dmp tables=emp,dept ;

Import: Release 10.2.0.1.0 - Production on Mon Apr 4 18:38:09 2011

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

Export file created by EXPORT:V10.02.01 via conventional path
import done in AL32UTF8 character set and AL16UTF16 NCHAR character set
. importing SCOTT's objects into SCOTT
. importing SCOTT's objects into SCOTT
. . importing table                         "DEPT"          4 rows imported
. . importing table                          "EMP"         14 rows imported
About to enable constraints...
Import terminated successfully without warnings.
[oracle@dba exp_dir]$

12.	导入到其他用户
	这样导入到的是system模式中去了
[oracle@dba exp_dir]$ imp userid=system/oracle file=schema.scott.dmp tables=emp,dept ;

Import: Release 10.2.0.1.0 - Production on Mon Apr 4 18:41:30 2011

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

Export file created by EXPORT:V10.02.01 via conventional path

Warning: the objects were exported by SCOTT, not by you

import done in AL32UTF8 character set and AL16UTF16 NCHAR character set
. importing SCOTT's objects into SYSTEM
. importing SCOTT's objects into SYSTEM
. . importing table                         "DEPT"          4 rows imported
. . importing table                          "EMP"         14 rows imported
About to enable constraints...
Import terminated successfully without warnings.
[oracle@dba exp_dir]$

使用touser参数 导入到指定用户  但userid的用户必须有权限 覆盖touser的权限的人才可以这样做
[oracle@dba exp_dir]$ imp userid=system/oracle touser=scott file=schema.scott.dmp tables=emp,dept ;

Import: Release 10.2.0.1.0 - Production on Mon Apr 4 18:42:01 2011

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

Export file created by EXPORT:V10.02.01 via conventional path

Warning: the objects were exported by SCOTT, not by you

import done in AL32UTF8 character set and AL16UTF16 NCHAR character set
. importing SCOTT's objects into SCOTT
. . importing table                         "DEPT"          4 rows imported
. . importing table                          "EMP"         14 rows imported
About to enable constraints...
Import terminated successfully without warnings.
[oracle@dba exp_dir]$

导入时追加数据，表不能有主键，正常导入时先建表 表存在就报错，加ignore=y选项 就是忽略表存在 追加数据

13.	导入的常用参数
	SHOW     just list file contents (N)
	COMMIT    commit array insert (N)
	BUFFER   size of data buffer
	很重要的两个参数 大表我们必须限制使用批量提交 以免回滚段小等问题
	commit=y		--降低导入的时候对回滚的压力。
				n -- 每张表数据导入完成后提交；
				y -- buffer满了以后就提交，一定要增大buffer的尺寸。

FULL         import entire file (N)

14.	备份表空间模式
	只是备份表空间中的存储对象 并不备份表空间自身的结构

[oracle@dba exp_dir]$ exp userid=system/oracle tablespaces=ts99 file=./tbs_ts99.dmp log=./tbs_ts99.log

SQL> drop tablespace ts99 including contents and datafiles;

Tablespace dropped.

SQL>

[oracle@dba exp_dir]$ imp userid=system/oracle file=./tbs_ts99.dmp full=y
.........
IMP-00003: ORACLE error 959 encountered
ORA-00959: tablespace 'TS99' does not exist
IMP-00017: following statement failed with ORACLE error 959:
.........

SQL> create tablespace ts99 datafile '/u01/oracle/oradata/ora10g/ts99.dbf' size 20M;

Tablespace created.

SQL>

[oracle@dba exp_dir]$ imp userid=system/oracle file=./tbs_ts99.dmp full=y

Import: Release 10.2.0.1.0 - Production on Tue Apr 5 03:18:47 2011

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

Export file created by EXPORT:V10.02.01 via conventional path
import done in AL32UTF8 character set and AL16UTF16 NCHAR character set
. importing SYSTEM's objects into SYSTEM
. importing U99's objects into U99
. . importing table                         "DEPT"          4 rows imported
. . importing table                          "EMP"         14 rows imported
About to enable constraints...
Import terminated successfully without warnings.
[oracle@dba exp_dir]$

15.	全库模式:
exp parfile=c:\\exp.txt
----------------------
userid=system/oracle
full=y								
filesize=50m							定义文件大小，切割备份，为将来传输方便。
file=(c:\\exp_full_1.dmp,c:\\exp_full_2.dmp)	定义各种文件的名字，如果名字不够的话，导出进程会挂起要文件名字。
buffer=10000000
feedback=10000
log=c:\\exp_full.log

imp parfile=c:\\imp.txt
-----------------------
userid=system/oracle
full=y
filesize=50m
file=(c:\\exp_full_1.dmp,c:\\exp_full_2.dmp)
buffer=10000000
feedback=10000
log=c:\\imp_full.log

16.	表空间传输
从一个数据库中将一个表空间迁移至另一个数据库
	1.将本地表空间设置为只读
	2.导出表空间元数据,将导出文件和表空间包含的数据文件拿到远程
	3.远程库要手动建立和本地同样的用户
	4.导入表空间元数据,并指定原来的datafile
	5.本地和远程表空间都恢复读写 正常使用
	
1.将本地表空间设置为只读
SQL> alter tablespace ts99 read only;

Tablespace altered.

SQL>

2.导出表空间元数据,将导出文件和表空间包含的数据文件拿到远程
[oracle@dba exp_dir]$ exp userid=\\''sys/oracle as sysdba'\\' tablespaces=ts99 transport_tablespace=y file=./trs_tbs_ts99.dmp

Export: Release 10.2.0.1.0 - Production on Tue Apr 5 03:27:01 2011

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
Export done in AL32UTF8 character set and AL16UTF16 NCHAR character set
Note: table data (rows) will not be exported
About to export transportable tablespace metadata...
For tablespace TS99 ...
. exporting cluster definitions
. exporting table definitions
. . exporting table                           DEPT
. . exporting table                            EMP
. exporting referential integrity constraints
. exporting triggers
. end transportable tablespace metadata export
Export terminated successfully without warnings.
[oracle@dba exp_dir]$

SQL> ! cp /u01/oracle/oradata/ora10g/ts99.dbf /u01/oracle/oradata/orcl/

SQL>

3.远程库要手动建立和本地同样的用户
SQL> select file_name,file_id,tablespace_name from dba_data_files;

FILE_NAME					 FILE_ID TABLESPACE_NAME
--------------------------------------------- ---------- ---------------
/u01/oracle/oradata/orcl/users01.dbf		       4 USERS
/u01/oracle/oradata/orcl/sysaux01.dbf		       3 SYSAUX
/u01/oracle/oradata/orcl/undotbs01.dbf		       2 UNDOTBS1
/u01/oracle/oradata/orcl/system01.dbf		       1 SYSTEM

SQL> create user u99 identified by u99;

User created.

SQL> grant connect,resource to u99;

Grant succeeded.

SQL>

4.导入表空间元数据,并指定原来的datafile
[oracle@dba exp_dir]$ export ORACLE_SID=newdb
[oracle@dba exp_dir]$ imp userid=\\''sys/oracle as sysdba'\\' file=./trs_tbs_ts99.dmp tablespaces=ts99 transport_tablespace=y datafiles=\\''/u01/oracle/oradata/orcl/ts99.dbf'\\'

Import: Release 10.2.0.1.0 - Production on Tue Apr 5 03:36:10 2011

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

Export file created by EXPORT:V10.02.01 via conventional path
About to import transportable tablespace(s) metadata...
import done in AL32UTF8 character set and AL16UTF16 NCHAR character set
. importing SYS's objects into SYS
. importing SYS's objects into SYS
. importing U99's objects into U99
. . importing table                         "DEPT"
. . importing table                          "EMP"
. importing SYS's objects into SYS
Import terminated successfully without warnings.
[oracle@dba exp_dir]$

SQL> select file_name,file_id,tablespace_NAME FROM DBA_DATA_FILES;

FILE_NAME					 FILE_ID TABLESPACE_NAME
--------------------------------------------- ---------- ---------------
/u01/oracle/oradata/newdb/users01.dbf		       4 USERS
/u01/oracle/oradata/newdb/sysaux01.dbf		       3 SYSAUX
/u01/oracle/oradata/newdb/undotbs01.dbf 	       2 UNDOTBS1
/u01/oracle/oradata/newdb/system01.dbf		       1 SYSTEM
/u01/oracle/oradata/orcl/ts99.dbf		       5 TS99

SQL>

5.本地和远程表空间都恢复读写 正常使用
SQL> alter tablespace ts99 read write;

Tablespace altered.

SQL> conn u99/u99
Connected.
SQL> select * from tab;

TNAME			       TABTYPE	CLUSTERID
------------------------------ ------- ----------
DEPT			       TABLE
EMP			       TABLE

SQL>

四	 权威资料

官方文档。

逻辑备份 Oracle 备份基础知识

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oracle数据库知识点分享专题二----逻辑备份

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