Steps for creating External Tables

1: Create Directory
CREATE DIRECTORY JAGAT_DIR AS 'C:\BALA';
GRANT READ ON DIRECTORY JAGAT_DIR TO PUBLIC;
GRANT READ ON DIRECTORY JAGAT_DIR TO PUBLIC;

2: Create a text file.--in demo.txt--- in JAGAT_DIR
7369,SMITH,CLERK,20
7499,ALLEN,SALESMAN,30
7521,WARD,SALESMAN,30
7566,JONES,MANAGER,20
7654,MARTIN,SALESMAN,30

Create Table ScriptCREATE TABLE ext_tab (empno CHAR(4),ename CHAR(20),
job CHAR(20),deptno CHAR(2))
ORGANIZATION EXTERNAL
( TYPE oracle_loader DEFAULT DIRECTORY JAGAT_DIR ACCESS PARAMETERS ( RECORDS DELIMITED BY NEWLINE BADFILE 'bad_%a_%p.bad' LOGFILE 'log_%a_%p.log' FIELDS TERMINATED BY ',' MISSING FIELD VALUES ARE NULL REJECT ROWS WITH ALL NULL FIELDS (empno, ename, job, deptno)) LOCATION ('demo.txt') )PARALLELREJECT LIMIT 0NOMONITORING;