[bbk5394] 第95集 -第12章 -数据移植 01

数据泵与原始Imp、exp命令比较

• Data pump是一个服务器端的工具;数据泵可以实现暂停功能;
• imp、exp是一个客户端的工具;

Oracle Data Pump:Overview

As a server-based facility for high-speed data and metadata movement,Oracle Data Pump:

• Is callable via DBMS_DATAPUMP
• Provides the following tools
  • expdp
  • impdp
  • Web-based interface
• Provides four data movement methods
  • Data file copying
  • Direct path
  • External tables
  • Network link support
• Detaches from and reattaches to long-running jobs
• Restarts Data Pump jobs

Oracle Data Pump:Benefits

Data Pump offers many benefits and some new features over earlier data movement tools ,such as:

• Fine-grained object and data selection
  • 以前导出时可以按照表、用户等粒度进行导出，现如今可以更加细粒度导出
  • 使用数据泵导出时，可以使用where条件进行更加细粒度的过滤
• Explicit specification of database version
  • 导出时，可以指定兼容的数据库版本（11g的数据库中导出兼容10g的数据库的数据
• Estimation of exprot job space consumption(expdp功能可以，在真正导出之前，模拟一次导出，从而估算出需要的空间，来保障本地磁盘空间充足，足以满足本次导出操作.)
• Network mode in a distributed enviromment
• Remapping capabilities
  • 将scott用户下的表，导出后，再倒入到test用户下，可以实现对象之间的映射
• Data sampling and metadata compression
• Compression of data during a Data Pump export
• Security through encryption
• Ability to export XML Type data as CLOBs
• Legacy mode to support old import and export files