exists ora oracle,转：oracle impdp的table_exists_action详解

1 table_exists_action参数说明

使用imp进行数据导入时，若表已经存在，要先drop掉表，再进行导入。

而使用impdp完成数据库导入时，若表已经存在，有四种的处理方式：

1)

skip：默认操作

2)

replace：先drop表，然后创建表，最后插入数据

3)

append：在原来数据的基础上增加数据

4) truncate：先truncate，然后再插入数据

2

实验预备

2.1

sys用户创建目录对象，并授权

SQL> create

directory dir_dump as '/home/oracle';

Directory created

SQL> grant read,

write on directory dir_dump to tuser;

Grant succeeded

2.2

导出数据

[oracle@cent4 ~]$ expdp

tuser/tuser directory=dir_dump dumpfile=expdp.dmp

schemas=tuser;

Export: Release 10.2.0.1.0 -

64bit Production on 星期五, 06 1月, 2012 20:44:22

Copyright (c) 2003, 2005,

Oracle. All rights reserved.

Connected to: Oracle Database

10g Enterprise Edition Release 10.2.0.1.0 - 64bit

Production

With the Partitioning, OLAP and

Data Mining options

Starting

"TUSER"."SYS_EXPORT_SCHEMA_01": tuser/********

directory=dir_dump dumpfile=expdp.dmp schemas=tuser

Estimate in progress using

BLOCKS method...

Processing object type

SCHEMA_EXPORT/TABLE/TABLE_DATA

Total estimation using BLOCKS

method: 128 KB

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

"TUSER"."TAB1" 5.25

KB 5 rows

. . exported

"TUSER"."TAB2" 5.296

KB 10 rows

Master table

"TUSER"."SYS_EXPORT_SCHEMA_01" successfully

loaded/unloaded

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

Dump file set for

TUSER.SYS_EXPORT_SCHEMA_01 is:

/home/oracle/expdp.dmp

Job

"TUSER"."SYS_EXPORT_SCHEMA_01" successfully completed at

20:47:29

2.3

查看已有两张表的数据

SQL> select *

from tab1;

A B

--- ----

1 11

2 22

3 33

4 44

5 55

SQL> select *

from tab2;

A B

--- ----

1 aa

2 bb

3 cc

4 dd

5 ee

6 ff

7 gg

8 hh

9 ii

10 jj

10 rows selected

3

replace

3.1

插入数据

SQL> insert into

tab1 (a, b) values (6, 66);

1 row inserted

SQL>

commit;

Commit complete

SQL> select *

from tab1;

A B

--- ----

1 11

2 22

3