[转自：http://space.itpub.net/519536/viewspace-631445]

当使用IMPDP完成数据库导入时，如遇到表已存在时，Oracle提供给我们如下四种处理方式：
a.忽略（SKIP，默认行为）；
b.在原有数据基础上继续增加（APPEND）；
c.先DROP表，然后创建表，最后完成数据插入（REPLACE）；
d.先TRUNCATE，再完成数据插入（TRUNCATE）。

真实感受一下这几种方式的效果，供参考。

1.IMPDP在线帮助中关于TABLE_EXISTS_ACTION参数的描述
TABLE_EXISTS_ACTION   Action to take if imported object already exists.
                      Valid keywords: (SKIP), APPEND, REPLACE and TRUNCATE.

2.Oracle官方文档中的描述
http://download.oracle.com/docs/cd/B19306_01/server.102/b14215/dp_import.htm#sthref365
Oracle官方文档是根本，需研读。

3.使用EXPDP生成一份dump文件
sec@secDB /expdp$ expdp sec/sec directory=expdp_dir dumpfile=`date +"%Y%m%d%H%M%S"`_sec.dmp logfile=`date +"%Y%m%d%H%M%S"`_sec.log

Export: Release 10.2.0.3.0 - 64bit Production on Thursday, 01 April, 2010 10:29:17

Copyright (c) 2003, 2005, Oracle.  All rights reserved.

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production
With the Partitioning, Oracle Label Security, OLAP and Data Mining Scoring Engine options
Starting "SEC"."SYS_EXPORT_SCHEMA_01":  sec/******** directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec.log
Estimate in progress using BLOCKS method...
Processing object type SCHEMA_EXPORT/TABLE/TABLE_DATA
Total estimation using BLOCKS method: 3 MB
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/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
. . exported "SEC"."T"                                   2.259 MB   24360 rows
Master table "SEC"."SYS_EXPORT_SCHEMA_01" successfully loaded/unloaded
******************************************************************************
Dump file set for SEC.SYS_EXPORT_SCHEMA_01 is:
  /expdp/20100401102917_sec.dmp
Job "SEC"."SYS_EXPORT_SCHEMA_01" successfully completed at 10:29:20

4.分别使用四中方式真实的感知一下具体效果
用到的IMPDP语句统一汇总在这里，方便参考。
impdp system/sys directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec_impdp.log TABLE_EXISTS_ACTION=SKIP
impdp system/sys directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec_impdp.log TABLE_EXISTS_ACTION=APPEND
impdp system/sys directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec_impdp.log TABLE_EXISTS_ACTION=REPLACE
impdp system/sys directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec_impdp.log TABLE_EXISTS_ACTION=TRUNCATE

1）默认行为SKIP
sec@ora10g> select count(*) from t;

COUNT(*)
----------
     24360

sec@secDB /expdp$ impdp system/sys directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec_impdp.log

Import: Release 10.2.0.3.0 - 64bit Production on Thursday, 01 April, 2010 10:50:41

Copyright (c) 2003, 2005, Oracle.  All rights reserved.

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production
With the Partitioning, Oracle Label Security, OLAP and Data Mining Scoring Engine options
Master table "SYSTEM"."SYS_IMPORT_FULL_01" successfully loaded/unloaded
Starting "SYSTEM"."SYS_IMPORT_FULL_01":  system/******** directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec_impdp.log
Processing object type SCHEMA_EXPORT/USER
ORA-31684: Object type USER:"SEC" already exists
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
ORA-39151: Table "SEC"."T" exists. All dependent metadata and data will be skipped due to table_exists_action of skip
Processing object type SCHEMA_EXPORT/TABLE/TABLE_DATA
Job "SYSTEM"."SYS_IMPORT_FULL_01" completed with 2 error(s) at 10:50:42

上面的行为与下面一条显示的指定“SKIP”效果是一样的，不赘述。
sec@secDB /expdp$ impdp system/sys directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec_impdp.log TABLE_EXISTS_ACTION=SKIP

2）APPEND方式
sec@secDB /expdp$ impdp system/sys directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec_impdp.log TABLE_EXISTS_ACTION=APPEND

Import: Release 10.2.0.3.0 - 64bit Production on Thursday, 01 April, 2010 10:51:32

Copyright (c) 2003, 2005, Oracle.  All rights reserved.

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production
With the Partitioning, Oracle Label Security, OLAP and Data Mining Scoring Engine options
Master table "SYSTEM"."SYS_IMPORT_FULL_01" successfully loaded/unloaded
Starting "SYSTEM"."SYS_IMPORT_FULL_01":  system/******** directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec_impdp.log TABLE_EXISTS_ACTION=APPEND
Processing object type SCHEMA_EXPORT/USER
ORA-31684: Object type USER:"SEC" already exists
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
ORA-39152: Table "SEC"."T" exists. Data will be appended to existing table but all dependent metadata will be skipped due to table_exists_action of append
Processing object type SCHEMA_EXPORT/TABLE/TABLE_DATA
. . imported "SEC"."T"                                   2.259 MB   24360 rows
Job "SYSTEM"."SYS_IMPORT_FULL_01" completed with 2 error(s) at 10:51:33

此时表T的记录数翻倍。
sec@ora10g> select count(*) from t;

COUNT(*)
----------
     48720

3）REPLACE方式
sec@secDB /expdp$ impdp system/sys directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec_impdp.log TABLE_EXISTS_ACTION=REPLACE

Import: Release 10.2.0.3.0 - 64bit Production on Thursday, 01 April, 2010 10:54:28

Copyright (c) 2003, 2005, Oracle.  All rights reserved.

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production
With the Partitioning, Oracle Label Security, OLAP and Data Mining Scoring Engine options
Master table "SYSTEM"."SYS_IMPORT_FULL_01" successfully loaded/unloaded
Starting "SYSTEM"."SYS_IMPORT_FULL_01":  system/******** directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec_impdp.log TABLE_EXISTS_ACTION=REPLACE
Processing object type SCHEMA_EXPORT/USER
ORA-31684: Object type USER:"SEC" already exists
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 "SEC"."T"                                   2.259 MB   24360 rows
Job "SYSTEM"."SYS_IMPORT_FULL_01" completed with 1 error(s) at 10:54:29

sec@ora10g> select count(*) from t;

COUNT(*)
----------
     24360

4）TRUNCATE方式
sec@secDB /expdp$ impdp system/sys directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec_impdp.log TABLE_EXISTS_ACTION=TRUNCATE

Import: Release 10.2.0.3.0 - 64bit Production on Thursday, 01 April, 2010 10:54:55

Copyright (c) 2003, 2005, Oracle.  All rights reserved.

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production
With the Partitioning, Oracle Label Security, OLAP and Data Mining Scoring Engine options
Master table "SYSTEM"."SYS_IMPORT_FULL_01" successfully loaded/unloaded
Starting "SYSTEM"."SYS_IMPORT_FULL_01":  system/******** directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec_impdp.log TABLE_EXISTS_ACTION=TRUNCATE
Processing object type SCHEMA_EXPORT/USER
ORA-31684: Object type USER:"SEC" already exists
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
ORA-39153: Table "SEC"."T" exists and has been truncated. Data will be loaded but all dependent metadata will be skipped due to table_exists_action of truncate
Processing object type SCHEMA_EXPORT/TABLE/TABLE_DATA
. . imported "SEC"."T"                                   2.259 MB   24360 rows
Job "SYSTEM"."SYS_IMPORT_FULL_01" completed with 2 error(s) at 10:54:56

sec@ora10g> select count(*) from t;

COUNT(*)
----------
     24360

5.小结
IMPDP的TABLE_EXISTS_ACTION参数相比IMP工具是一个进步，我们的控制手段得到加强，莫要固步自封。

impdp参数TABLE_EXISTS_ACTION的更多相关文章

  1. Oracle10g数据泵impdp参数详解--摘自网络

    Oracle10g数据泵impdp参数详解 2011-6-30 12:29:05 导入命令Impdp •      ATTACH 连接到现有作业, 例如 ATTACH [=作业名]. •      C ...

  2. oracle impdp的table_exists_action详解

    oracle impdp的table_exists_action详解 分类: [oracle]--[备份与恢复]2012-01-06 22:44 9105人阅读 评论(0) 收藏 举报 tableac ...

  3. expdp impdp 参数

    With the Partitioning, OLAP, Data Mining and Real Application Testing options启动 "BEMIS".&q ...

  4. oracle impdp 覆盖导入 table_exists_action关键字使用

    oracle10g之后impdp的table_exists_action参数table_exists_action选项:{skip 是如果已存在表,则跳过并处理下一个对象:append是为表增加数据: ...

  5. Oracle简单常用的数据泵导出导入(expdp/impdp)命令举例(下)

    <Oracle简单常用的数据泵导出导入(expdp/impdp)命令举例(上)> <Oracle简单常用的数据泵导出导入(expdp/impdp)命令举例(下)> 目的:指导项 ...

  6. Oracle基础 数据泵导出/导入Expdp/impdp(转)

    一.EXPDP和IMPDP使用说明 Oracle Database 10g引入了最新的数据泵(Data Dump)技术,数据泵导出导入(EXPDP和IMPDP)的作用 1)实现逻辑备份和逻辑恢复. 2 ...

  7. oracle两种导出导入方式，即imp与impdp之比较

    尽管使用了很多次impexp及impdpexpdp但是使用起来还是会遇到很多问题,现总结如下: 应用:将一个用户的所有表结构及索引,触发器,过程,函数等导入到另一用户里 imp/exp 导出用户表结构 ...

  8. Oracle 11g R2 Backup Data Pump(数据泵)之expdp/impdp工具

    Oracle Data Pump(以下简称数据泵)是Oracle 10g开始提供的一种数据迁移工具,同时也被广大DBA用来作为数据库的逻辑备份工具和体量较小的数据迁移工具.与传统的数据导出/导入工具, ...

  9. linux下用数据泵导入导出（impdp、expdp）

    expdp和impdp expdp假设a用户的默认表空间是a,导出用户a所有数据: 如果是多实例 需要在命令行或终端手工指定实例 set ORACLE_SID=实例名 否则回报ORA-12560: T ...

随机推荐

  1. HDU 5038 Grade (水题，坑题)

    题意:给 n 个数,输出众数,但是如果所有的频率都相同但数不同输出 Bad Mushroom. 析:直接记录个数直接暴力就,就是要注意只有一种频率的时候. 代码如下: #pragma comment( ...

  2. 20169219《Linux内核原理及分析》第十二周作业

    格式化字符串漏洞实验 格式化字符串攻击原理是利用格式化函数(如printf())的沿着堆栈指针向下打印的特性,通过只提供格式化字符串但不提供对应的变量,读取栈内空间的内容. 更进一步,通过将某个要攻击 ...

  3. <超越死亡：恩宠与勇气>节选

    我有一副身体,但我并非自己的身体.我可以看见并感觉到我的身体,然而凡是可以被看见以及被感觉到的,并不是真正的观者.我的身体也许疲惫或兴奋,生病或健康,沉重或轻松,也可能焦虑或平静,但这与内在的真我全然 ...

  4. 动态横向(水平)合并GridView数据行DataRow的列

    前一段时间,Insus.NET有写过<动态合并GridView数据行DataRow的列>http://www.cnblogs.com/insus/p/3238348.html, 那是纵向( ...

  5. spring mvc常用注解标签

    @Controller 在SpringMVC 中,控制器Controller 负责处理由DispatcherServlet 分发的请求,它把用户请求的数据经过业务处理层处理之后封装成一个Model , ...

  6. 利用filter，巧妙地去除Array的重复元素

    var r, arr = ['apple', 'strawberry', 'banana', 'pear', 'apple', 'orange', 'orange', 'strawberry']; r ...

  7. 「BZOJ 1297」「SCOI 2009」迷路「矩阵乘法」

    题意 边权\(w \in [1, 9]\)的\(n\)个结点的有向图,图上从\(1\)到\(n\)长度为\(d\)的路径计数,\(n \leq 10\). 题解 如果边权为\(1\)很经典,设\(f[ ...

  8. A Plug for UNIX UVA - 753（网络流）

    题意:n个插座,m个设备及其插头类型,k种转换器,没有转换器的情况下插头只能插到类型名称相同的插座中,问最少剩几个不匹配的设备 lrj紫书里面讲得挺好的. 先跑一遍floyd,看看插头类型a能否转换为 ...

  9. Leveling Ground（数论，三分法，堆）

    Leveling Ground(数论,三分法,堆) 给定n个数和a,b每次可以选择一段区间+a,-a,+b或-b,问最少操作几次能把他们都变成0.n<=1e5. 首先差分一下序列,问题就会变成了 ...

  10. P2597 [ZJOI2012]灾难

    \(\color{#0066ff}{ 题目描述 }\) 阿米巴是小强的好朋友. 阿米巴和小强在草原上捉蚂蚱.小强突然想,如果蚂蚱被他们捉灭绝了,那么吃蚂蚱的小鸟就会饿死,而捕食小鸟的猛禽也会跟着灭绝, ...