impdp自动创建用户前提条件与应用场景

impdp命令在导入数据时,如果用户存在,则会自动创建该用户,因为expdp导出的dmp文件中包含了创建用户的脚本信息(包括密码,缺省表空间,临时表空间等)。

impdp自动创建用户有一个前提条件，就是需要首先创建用户的缺省表空间和临时表空间，如果缺省表空间或者临时表空间不存在，则自动创建用户会失败，导致导入数据的失败。

下面通过实验来描述impdp自动创建用户的前提条件和应用场景

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一. 创建表空间和用户

SQL> create tablespace aidu datafile '/oradata/gridctl/aidu01.dbf' size 128m extent management local segment space management auto logging;

Tablespace created.

SQL> create temporary tablespace temp2 tempfile '/oradata/gridctl/temp021.dbf' size 128m extent management local;

Tablespace created.

SQL> create user aidu profile default identified by "aidutest" default tablespace aidu temporary tablespace temp2 account unlock;

User created.

SQL> grant resource,connect to aidu;

Grant succeeded.

SQL> conn aidu/aidutest

Connected.

SQL> create table test (id number(10) not null,name varchar2(20));

Table created.

SQL> insert into test values(1,'first');

1 row created.

SQL> insert into test select id+1,name from test;

1 row created.

SQL> insert into test select id+2,name from test;

2 rows created.

SQL> select * from test;

ID NAME

---------- --------------------

1 first

2 first

3 first

4 first

SQL> commit;

Commit complete.

二.创建DIRECTORY,导出用户的数据

##为expdp,impdp建立directory

SQL>create directory impdp as '/oradata/gridctl' ;

SQL>grant read,write on directory impdp to aidu;

[oracle@primarydb ~]$ expdp system/****** schemas=aidu directory=impdp dumpfile=aidu2.dmp

Export: Release 10.2.0.4.0 - 64bit Production on Friday, 11 February, 2011 8:36:18

Copyright (c) 2003, 2007, Oracle. All rights reserved.

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bit Production

With the Partitioning, OLAP, Data Mining and Real Application Testing options

Starting "SYSTEM"."SYS_EXPORT_SCHEMA_01": system/******** schemas=aidu directory=impdp dumpfile=aidu.dmp

Estimate in progress using BLOCKS method...

......

Processing object type SCHEMA_EXPORT/TABLE/TABLE

. . exported "AIDU"."TEST" 5.304 KB 4 rows

Master table "SYSTEM"."SYS_EXPORT_SCHEMA_01" successfully loaded/unloaded

******************************************************************************

Dump file set for SYSTEM.SYS_EXPORT_SCHEMA_01 is:

/oradata/aidu.dmp

Job "SYSTEM"."SYS_EXPORT_SCHEMA_01" successfully completed at 08:36:36

[oracle@primarydb oradata]$ ls -lt aidu*

-rw-r----- 1 oracle oinstall 155648 Feb 11 08:36 aidu.dmp

三.删除用户,删除用户的表空间和临时表空间

SQL> drop user aidu cascade;

User dropped.

SQL> drop tablespace aidu including contents;

Tablespace dropped.

SQL> drop tablespace temp2 including contents;

Tablespace dropped.

SQL> exit

四.导入用户数据,测试是否可以自动创建用户

[oracle@primarydb oradata]$ impdp system/****** directory=impdp dumpfile=aidu.dmp

。。。。。。

Master table "SYSTEM"."SYS_IMPORT_FULL_01" successfully loaded/unloaded

Starting "SYSTEM"."SYS_IMPORT_FULL_01": system/******** directory=impdp dumpfile=aidu2.dmp

Processing object type SCHEMA_EXPORT/USER

ORA-39083: Object type USER failed to create with error:

ORA-00959: tablespace 'AIDU' does not exist

Failing sql is:

CREATE USER "AIDU" IDENTIFIED BY VALUES 'FBF36F881A20141D' DEFAULT TABLESPACE "AIDU" TEMPORARY TABLESPACE "TEMP2"

Processing object type SCHEMA_EXPORT/SYSTEM_GRANT

ORA-39083: Object type SYSTEM_GRANT failed to create with error:

ORA-01917: user or role 'AIDU' does not exist

Failing sql is:

GRANT UNLIMITED TABLESPACE TO "AIDU"

。。。。。。

Processing object type SCHEMA_EXPORT/TABLE/TABLE

ORA-39083: Object type TABLE failed to create with error:

ORA-01918: user 'AIDU' does not exist

Failing sql is:

CREATE TABLE "AIDU"."TEST" ("ID" NUMBER(10,0) NOT NULL ENABLE, "NAME" VARCHAR2(20)) PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT) TABLESPACE "AIDU"

Processing object type SCHEMA_EXPORT/TABLE/TABLE_DATA

Job "SYSTEM"."SYS_IMPORT_FULL_01" completed with 7 error(s) at 09:26:51

可以看到自动创建用户时,因为用户表空间和临时表空间不存在,所以创建用户失败,报错为:

Failing sql is:

CREATE USER "AIDU" IDENTIFIED BY VALUES 'FBF36F881A20141D' DEFAULT TABLESPACE "AIDU" TEMPORARY TABLESPACE "TEMP2"

笔者曾经尝试只建立用户表空间aidu,但不去建立临时表空间,尝试导入用户数据,自动创建用户仍然失败.所以用户表空间和临时表空间都需要在导入前存在.

五.创建用户表空间和临时表空间,为导入数据做好准备

SQL> create tablespace aidu datafile '/oradata/gridctl/aidu01.dbf' size 128m reuse extent management local segment space management auto logging;

Tablespace created.

SQL> create temporary tablespace temp2 tempfile '/oradata/gridctl/temp021.dbf' size reuse 128m extent management local;

Tablespace created.

六.使用impdp导入用户数据,自动创建用户成功.

[oracle@primarydb oradata]$ impdp system/aidu2010 directory=impdp dumpfile=aidu.dmp

。。。。。。

Master table "SYSTEM"."SYS_IMPORT_FULL_01" successfully loaded/unloaded

Starting "SYSTEM"."SYS_IMPORT_FULL_01": system/******** directory=impdp dumpfile=aidu.dmp

Processing object type SCHEMA_EXPORT/USER

Processing object type SCHEMA_EXPORT/SYSTEM_GRANT

Processing object type SCHEMA_EXPORT/ROLE_GRANT

Processing object type SCHEMA_EXPORT/DEFAULT_ROLE

Processing object type SCHEMA_EXPORT/PRE_SCHEMA/PROCACT_SCHEMA

Processing object type SCHEMA_EXPORT/TABLE/TABLE

Processing object type SCHEMA_EXPORT/TABLE/TABLE_DATA

. . imported "AIDU"."TEST" 5.304 KB 4 rows

Job "SYSTEM"."SYS_IMPORT_FULL_01" successfully completed at 08:49:42

[oracle@primarydb oradata]$ sqlplus aidu/aidutest

SQL> select * from test;

ID NAME

---------- --------------------

1 first

2 first

3 first

4 first

总结:

impdp 是可以自动创建用户,但有一个前提条件:用户的缺省表空间和临时表空间要先创建好(存在).

使用impdp自动创建用户应用场景:

1.数据库数据迁移或者升级到另外一个数据库环境,并且数据库中有很多用户,DBA无法知道每一个用户的密码,只能查到用户的缺省表空间和临时表空间.

2.DBA不能重设用户的密码,重设密码将会导致很多旧的应用系统需要进行配置,存在一定的风险.

3.新的数据库的IP,PORT都与旧的相同,应用系统机会不需要做任何修改.

通过impdp创建用户可以保留用户的密码信息,应用系统不需要进行配置.

附查询用户缺省表空间与临时表空间的SQL语句:

SQL> select username,default_tablespace,temporary_tablespace from dba_users;

USERNAME DEFAULT_TABLESPACE TEMPORARY_TABLESPACE

------------------------------ ------------------------------ ------------------------------

AIDU AIDU TEMP2

OUTLN SYSTEM TEMPTS1

SYS SYSTEM TEMPTS1

SYSTEM SYSTEM TEMPTS1

DBSNMP SYSAUX TEMPTS1

MGMT_VIEW MGMT_TABLESPACE TEMPTS1

SYSMAN MGMT_TABLESPACE TEMPTS1

WMSYS SYSAUX TEMPTS1

TSMSYS USERS TEMPTS1

DIP USERS TEMPTS1

ORACLE_OCM USERS TEMPTS1

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