不同版本exp/imp使用注意事项

在进行数据迁移，常用到exp/imp工具，该工具可以跨平台、版本。下面介绍下在使用不同版本的exp/imp时候的注意事项
    官网说明如下
    http://docs.oracle.com/cd/E11882_01/server.112/e22490/original_export.htm#SUTIL2103
 
  使用不同版本的exp/imp
        无论在什么时候，在不同版本的oracle 数据库中迁移数据时，都必须要遵守如下的基本规则

1.        1.  imp工具的版本必须和目标库的版本相同。例如，使用版本为9.2.0.7的imp工具导入到版本为9.2.0.8的数据库中，会遇到错误。
2.        2. exp工具的版本必须与源库或者目标库中版本较低的相同。

         例如，从低版本的源库exp导出数据，imp导入到高本版目标库，那么exp的版本必须要和源库相同。同理，
                    从高版本的源库exp导出数据，imp导入到低版本目标库，那么exp的版本必须和目标库相同。
    
    使用不同版本的exp/imp的约束     

1.     1. exp工具导出的dmp文件，只能用imp工具导入。也就是说exp/imp配对使用，expdp/impdp配对使用 。exp导出的dmp文件无法用impdp导入。
2.     2. 任何exp导出的文件，都可以imp到高版本的数据库中。也就是说，exp/imp向下兼容。
3.     3. 低版本的imp工具无法读取高版本的exp导出的文件。例如9.2 exp导出的dmp文件无法用9.0.1版本的imp工具导入。
4.     4. whenever a lower version of the Export utility runs with a later release of the Oracle database, categories of database objects that did not exist in the earlier release are excluded from the export.

  
    不同版本exp/imp迁移数据参照表  ，参见文章末尾处 表21-5

  
Using Different Releases of Export and Import

This section describes compatibility issues that relate to using different releases of Export and the Oracle database.

Whenever you are moving data between different releases of the Oracle database, the following basic rules apply:

• The Import utility and the database to which data is being imported (the target database) must be the same release. For example, if you try to use the Import utility 9.2.0.7 to import into a 9.2.0.8 database, then you may encounter errors.

• The version of the Export utility must be equal to the release of either the source or target database, whichever is earlier.

  For example, to create an export file for an import into a later release database, use a version of the Export utility that equals the source database. Conversely, to create an export file for an import into an earlier release database, use a version of the Export utility that equals the release of the target database.

  • In general, you can use the Export utility from any Oracle8 release to export from an Oracle9i server and create an Oracle8 export file.

Restrictions When Using Different Releases of Export and Import

The following restrictions apply when you are using different releases of Export and Import:

• Export dump files can be read only by the Import utility because they are stored in a special binary format.

• Any export dump file can be imported into a later release of the Oracle database.

• The Import utility cannot read export dump files created by the Export utility of a later maintenance release. For example, a release 9.2 export dump file cannot be imported by a release 9.0.1 Import utility.

• Whenever a lower version of the Export utility runs with a later release of the Oracle database, categories of database objects that did not exist in the earlier release are excluded from the export.

• Export files generated by Oracle9i Export, either direct path or conventional path, are incompatible with earlier releases of Import and can be imported only with Oracle9i Import. When backward compatibility is an issue, use the earlier release or version of the Export utility against the Oracle9idatabase.

Examples of Using Different Releases of Export and Import

Table 21-5 shows some examples of which Export and Import releases to use when moving data between different releases of the Oracle database.

Table 21-5 Using Different Releases of Export and Import

Export from->Import toUse Export ReleaseUse Import Release

8.1.6 -> 8.1.6

8.1.6

8.1.6

8.1.5 -> 8.0.6

8.0.6

8.0.6

8.1.7 -> 8.1.6

8.1.6

8.1.6

9.0.1 -> 8.1.6

8.1.6

8.1.6

9.0.1 -> 9.0.2

9.0.1

9.0.2

9.0.2 -> 10.1.0

9.0.2

10.1.0

10.1.0 -> 9.0.2

9.0.2

9.0.2

Table 21-5 covers moving data only between the original Export and Import utilities. For Oracle Database 10g release 1 (10.1) or higher, Oracle recommends the Data Pump Export and Import utilities in most cases because these utilities provide greatly enhanced performance compared to the original Export and Import utilities.