Oracle Data Pump is made up of three distinct parts:
The command-line clients, expdp and impdp
The DBMS_DATAPUMP PL/SQL package (also known as the Data Pump API)
The DBMS_METADATA PL/SQL package (also known as the Metadata API)
The Data Pump clients, expdp and impdp, start the Data Pump Export utility and Data Pump Import utility, respectively.
The expdp and impdp clients use the procedures provided in the DBMS_DATAPUMP PL/SQL package to execute export and import commands, using the parameters entered at the command line. These parameters enable the exporting and importing of data and metadata for a complete database or for subsets of a database.
When metadata is moved, Data Pump uses functionality provided by the DBMS_METADATA PL/SQL package. The DBMS_METADATA package provides a centralized facility for the extraction, manipulation, and re-creation of dictionary metadata.
The DBMS_DATAPUMP and DBMS_METADATA PL/SQL packages can be used independently of the Data Pump clients.
All Data Pump Export and Import processing, including the reading and writing of dump files, is done on the system (server) selected by the specified database connect string. This means that for unprivileged users, the database administrator (DBA) must create directory objects for the Data Pump files that are read and written on that server file system. (For security reasons, DBAs must ensure that only approved users are allowed access to directory objects.) For privileged users, a default directory object is available. See "Default Locations for Dump_ Log_ and SQL Files" for more information about directory objects.
Oracle Database PL/SQL Packages and Types Reference for a description of the DBMS_DATAPUMP package
Oracle Database PL/SQL Packages and Types Reference for a description of the DBMS_METADATA package
Oracle Database SecureFiles and Large Objects Developer's Guide for information about guidelines to consider when creating directory objects