External tables

External tables allow Oracle to query data that is stored outside the database in flat files. 
The ORACLE_LOADER driver can be used to access any data stored in any format 
that can be loaded by SQL*Loader. 

No DML can be performed on external tables but they can be used for query, join and sort operations.

SQLPLUS SYS/ADMIN AS SYSDBA

CREATE DIRECTORY NEW AS 'D:\NEW';

CREATE TABLE countries_ext (
  country_code      VARCHAR2(5),
  country_name      VARCHAR2(50),
  country_language  VARCHAR2(50)
)
ORGANIZATION EXTERNAL (
  TYPE ORACLE_LOADER
  DEFAULT DIRECTORY NEW
  ACCESS PARAMETERS (
    RECORDS DELIMITED BY NEWLINE
    FIELDS TERMINATED BY ','
    MISSING FIELD VALUES ARE NULL
    (
      country_code      CHAR(5),
      country_name      CHAR(50),
      country_language  CHAR(50)
    )
  )
  LOCATION ('Countries1.txt','Countries2.txt')
)
PARALLEL 5
REJECT LIMIT UNLIMITED;

SELECT *
FROM   countries_ext
ORDER BY country_name;