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HomeDatabaseMysql Tutorial对imp中的fromuser参数的偏差理解

这两天执行导入dump文件时总碰到一个问题。 问题现象 : 1. 执行:imp xyz/xxx file=test.dmp log=imp_test.log fromuser=test1 touser=test2ignore=y commit=y buffer=300000000 feedback=10000 注:这个文件dump200G容量。 2. 执行了许久,但最后结果和log

这两天执行导入dump文件时总碰到一个问题。

问题现象

1. 执行:imp xyz/xxx file=test.dmp log=imp_test.log fromuser=test1 touser=test2 ignore=y commit=y buffer=300000000 feedback=10000

注:这个文件dump>200G容量。

2. 执行了许久,但最后结果和log中记录:

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production
With the Partitioning and Data Mining options

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

Warning: the objects were exported by TEST1, not by you

import done in ZHS16GBK character set and AL16UTF16 NCHAR character set
. importing TEST1's objects into TEST2
Import terminated successfully without warnings.

3. 但没有任何dump中的数据导入到test2用户中。

原因分析

首先,其实是对imp命令中的fromuser参数偏差的理解。

[root@vm-vmw4131-t ~]# imp -help

FROMUSER list of owner usernames

imp指令帮助中说明FROMUSER的含义是“属主用户名列表”,相应的,从exp指令帮助中可以看到OWNER参数表示的是相同的含义:

[root@vm-vmw4131-t ~]# exp -help

OWNER list of owner usernames

即该用户指的是对象所属用户。

其次,经过咨询,上述问题中用到的fromuser=test1这个test1用户是执行exp的系统账户,并不是数据库对象所属账户,这就能解释上面问题的原因了:由于dump文件所属的数据对象账户是另外一个账户,不是test1,因此使用imp ... fromuser=test1时,会检索这个文件dump,查找属于test1用户的对象,全文件扫描后,根本没有属于该用户的对象,因此提示“Import terminated successfully without warnings”正常结束。

总结

1. 这次导入导出时可能根本没实际考虑LANG等字符集环境变量。

2. imp的fromuser指的是对象所属用户,不是执行exp导出的用户。

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