expdp是否删除了Oracle中的数据？

Question

我将在Hadoop集群上执行升级，但我想先备份Ambari Metastore架构，以防出现任何问题。

Oracle用于存储数据，因此我查看了如何使用expdp在当前状态下快速备份模式。但是，我在几个不同的文档中看到，它被用来“卸载”数据。这是否意味着在转储过程中数据将从数据库中删除？我想保持一切就绪并快速备份，类似于Postgres命令pg_dump。

Answer 1

别担心，您的数据将保持原样。

这是一个简单的例子：我正在导出Scott的DEPT表。在EXPDP执行之前和之后，您将看到数据在表中。

SQL> select * from dept;

    DEPTNO DNAME          LOC
---------- -------------- -------------
        10 ACCOUNTING     NEW YORK
        20 RESEARCH       DALLAS
        30 SALES          CHICAGO
        40 OPERATIONS     BOSTON

SQL> $expdp scott/tiger@xe tables=dept directory=ext_dir

Export: Release 11.2.0.2.0 - Production on Pon O×u 5 21:21:24 2018

Copyright (c) 1982, 2009, Oracle and/or its affiliates.  All rights reserved.

Connected to: Oracle Database 11g Express Edition Release 11.2.0.2.0 - 64bit Production
Starting "SCOTT"."SYS_EXPORT_TABLE_01":  scott/********@xe tables=dept directory=ext_dir
Estimate in progress using BLOCKS method...
Processing object type TABLE_EXPORT/TABLE/TABLE_DATA
Total estimation using BLOCKS method: 64 KB
Processing object type TABLE_EXPORT/TABLE/TABLE
Processing object type TABLE_EXPORT/TABLE/INDEX/INDEX
Processing object type TABLE_EXPORT/TABLE/CONSTRAINT/CONSTRAINT
Processing object type TABLE_EXPORT/TABLE/INDEX/STATISTICS/INDEX_STATISTICS
Processing object type TABLE_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS
. . exported "SCOTT"."DEPT"                              5.929 KB       4 rows
Master table "SCOTT"."SYS_EXPORT_TABLE_01" successfully loaded/unloaded
******************************************************************************
Dump file set for SCOTT.SYS_EXPORT_TABLE_01 is:
  C:\TEMP\EXPDAT.DMP
Job "SCOTT"."SYS_EXPORT_TABLE_01" successfully completed at 21:21:34


SQL> select * from dept;

    DEPTNO DNAME          LOC
---------- -------------- -------------
        10 ACCOUNTING     NEW YORK
        20 RESEARCH       DALLAS
        30 SALES          CHICAGO
        40 OPERATIONS     BOSTON

SQL>