External Tables - Oracle 10g/11g Data and Database Management Utilities - page 57

external plain file

ORACLE_LOADER

ORACLE_DATAPUMP

SQL>SELECT*
FROM EXT_TAB;

external dump file

A second driver is available, the ORACLE_DATAPUMP access driver, which uses
the Data Pump technology to read the table and unload data to an External Table.
This driver allows the user to perform a logical backup that can later be read back
to the database without actually loading the data. The ORACLE_DATAPUMP access
driver utilizes a proprietary binary format for the external file, so it is not possible
to view it as a flat file.

Let's setup the environment
Let's create the demonstration user, and prepare its environment to create an
External Table . The example that will be developed first refers to the External Table
using the ORACLE_LOADER driver.

create user EXTTABDEMO
identified by ORACLE
default tablespace USERS;
alter user exttabdemo
quota unlimited on users;
grant CREATE SESSION,
CREATE TABLE,
CREATE PROCEDURE,
CREATE MATERIALIZED VIEW,
ALTER SESSION,
CREATE VIEW,
CREATE ANY DIRECTORY
to EXTTABDEMO;