One of the main uses of the External Tables is their support of the ETL process, allowing the user to perform a data load that is transformed to the target format without an intermediate stage table.
Let's read an External Table whose contents are:
This data can be loaded in a single command to multiple tables. Let's create several tables with the same structure:
SQL> desc amount_jan
Name Null? Type
----------------- -------- ------------
REGION VARCHAR2(16)
AMOUNT NUMBER(3)
Now we can issue a command to send the data from the External Table to the different tables.
INSERT ALL INTO AMOUNT_JAN (REGION, AMOUNT) VALUES(COUNTRY, JAN) INTO AMOUNT_FEB (REGION, AMOUNT) VALUES(COUNTRY, FEB) INTO AMOUNT_MAR (REGION, AMOUNT) VALUES(COUNTRY, JAN) INTO AMOUNT_APR (REGION, AMOUNT) VALUES(COUNTRY, JAN) INTO AMOUNT_MAY (REGION, AMOUNT) VALUES(COUNTRY, JAN) INTO AMOUNT_JUN (REGION, AMOUNT) VALUES(COUNTRY...