Oracle External Table

Oracle External Table:- Oracle External Table are use for the purpose of load data  from external sources such as spreadsheet data (csv format) , text file or any others. 

Limitations of  External Tables  
There are some limitations  to using external table

DML Operation are not support. Oracle external tables are read-only, but the base data can be edited in any text editor. Poor response for high-volume queries.

CREATE OR REPLACE DIRECTORY
DATA_FILE  AS
'D:\app\';


CREATE TABLE ext_table(
emp_id    VARCHAR2(20),
emp_name  VARCHAR2(150),
COMMENTS       VARCHAR2(300)
)
ORGANIZATION EXTERNAL (
TYPE oracle_loader
DEFAULT DIRECTORY DATA_FILE
ACCESS PARAMETERS (
RECORDS DELIMITED BY NEWLINE
LOGFILE 'data.log'
BADFILE 'data.txt'
FIELDS TERMINATED BY ','
MISSING FIELD VALUES ARE NULL
)
LOCATION('Data.csv')
)
REJECT LIMIT UNLIMITED;