从本节开始，将介绍下如何将单实例数据库迁移到rac环境。在生产环境中，随着业务和数据量的加大，这种需求和场景不可避免，一般来
从本节开始，将介绍下如何将单实例数据库迁移到rac环境。在生产环境中，随着业务和数据量的加大，这种需求和场景不可避免，一般来讲主要由以下四种方法实现迁移过程!
1：使用expdp/impdp数据泵导出导入，或者使用传统的exp/imp导入导出，后者效率低下；
2: 使用在线表空间迁移技术快速导出导入，前提是数据库的字符集要一致；
3：使用rman的备份进行异机恢复
4: 对单实例数据库构建基于rac的物理备库，进而切换备库为主库，这是生产环境中最为推荐的做法
本节中介绍使用expdp/impdp数据泵导出导入的方式实现迁移！
环境介绍：
数据库的版本均为10.2.0.5
操作系统的版本单实例数据库(源库)为rhel5.4 64 bit
rac(目标数据库)为ceontos4.8 64bit
一：查看源库的版本和表空间情况，同时在源库上建新的表空间和用户，插入数据，建立索引，，创建目录对象，使用expdp到出用户的schema等
SQL> select * from v$version;
BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bi
PL/SQL Release 10.2.0.5.0 - Production
CORE 10.2.0.5.0 Production
TNS for Linux: Version 10.2.0.5.0 - Production
NLSRTL Version 10.2.0.5.0 - Production
SQL> show parameter compat;
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
compatible string 10.2.0.5.0
plsql_v2_compatibility boolean FALSE
SQL> 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
SQL> create tablespace exp_rac datafile
2 '/u01/app/oracle/oradata/orcl/exp_rac01.dbf' size 300M
3 autoextend on next 10M maxsize unlimited
4* extent management local
Tablespace created.
SQL> create tablespace exp_rac_index datafile
2 '/u01/app/oracle/oradata/orcl/exp_rac_index01.dbf' size 300M
3 autoextend on next 10M maxsize unlimited
4* extent management local
Tablespace created.
SQL> 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
EXP_RAC /u01/app/oracle/oradata/orcl/exp_rac01.dbf
EXP_RAC_INDEX /u01/app/oracle/oradata/orcl/exp_rac_index01.dbf
SQL> create user test1 identified by oracle
2 default tablespace exp_rac
3 temporary tablespace temp
4 quota unlimited on exp_rac
5* account unlock;
User created.
SQL> grant connect,resource to test1;
Grant succeeded.
SQL> create table test1.source as select * from dba_source;
Table created.
SQL> insert into test1.source select * from test1.source;
295491 rows created.
SQL> /
590982 rows created.
SQL> /
1181964 rows created.
SQL> commit;
Commit complete.
SQL> analyze table test1.source compute statistics;
Table analyzed.
SQL> select count(*) from test1.source;
COUNT(*)
----------
2363928
SQL> select sum(bytes/(1024*1024)) MB from dba_extents
2 where segment_name='SOURCE'
3 and owner='TEST1';
MB
----------
408
[oracle@server49 orcl]$ ll -h exp_rac01.dbf
-rw-r----- 1 oracle oinstall 411M Jan 1 19:06 exp_rac01.dbf
SQL> create index test1.i_source
2 on test1.source(type)
3 tablespace exp_rac_index;
Index created.
SQL> select table_name,tablespace_name from dba_indexes
2 where owner='TEST1' and index_name='I_SOURCE';
TABLE_NAME TABLESPACE_NAME
------------------------------ --------------------
SOURCE EXP_RAC_INDEX
SQL> create directory expdp_dir as '/home/oracle/expdp_dir';
Directory created.
SQL> grant read,write on directory expdp_dir to test1;
Grant succeeded.
SQL> !mkdir -p /home/oracle/expdp_dir
[oracle@server49 ~]$ expdp test1/oracle directory=expdp_dir dumpfile=source.dmp logfile=source.log schemas=test1
Export: Release 10.2.0.5.0 - 64bit Production on Sunday, 01 January, 2012 19:38:30
Copyright (c) 2003, 2007, Oracle. All rights reserved.
Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
Starting "TEST1"."SYS_EXPORT_SCHEMA_01": test1/******** directory=expdp_dir dumpfile=source.dmp logfile=source.log schemas=test1
Estimate in progress using BLOCKS method...
Processing object type SCHEMA_EXPORT/TABLE/TABLE_DATA
Total estimation using BLOCKS method: 408 MB
Processing object type SCHEMA_EXPORT/PRE_SCHEMA/PROCACT_SCHEMA
Processing object type SCHEMA_EXPORT/TABLE/TABLE
Processing object type SCHEMA_EXPORT/TABLE/INDEX/INDEX
Processing object type SCHEMA_EXPORT/TABLE/CONSTRAINT/CONSTRAINT
Processing object type SCHEMA_EXPORT/TABLE/INDEX/STATISTICS/INDEX_STATISTICS
Processing object type SCHEMA_EXPORT/TABLE/COMMENT
Processing object type SCHEMA_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS
. . exported "TEST1"."SOURCE" 280.8 MB 2363928 rows
Master table "TEST1"."SYS_EXPORT_SCHEMA_01" successfully loaded/unloaded
******************************************************************************
Dump file set for TEST1.SYS_EXPORT_SCHEMA_01 is:
/home/oracle/expdp_dir/source.dmp
Job "TEST1"."SYS_EXPORT_SCHEMA_01" successfully completed at 19:39:03
二：复制impdp导出的相关文件到目标库上,同时在目标库上创建相应的用户和表空间以及目录对象等