OTN Appreciation Day : External tables

As part of the OTN Appreciation Day (see https://oracle-base.com/blog/2016/09/28/otn-appreciation-day/) I’m writing about one of my favorite Oracle features: External tables.

Traditionally people loaded data in an Oracle database using SQL*Loader. With the introduction of external tables, SQL*Loader became obsolete (in my view ;-)), because external tables provide the same loading capabilities and so much more than SQL*loader. Why? Because external tables can be accessed through SQL. You have all possibilities SQL-queries offer. Prallelism, difficult joins with internal or other external tables and of course all complex operations SQL allows. ETL became much easier using external tables, because it allowed to process data through SQL joins and filters already before it was loaded in the database.

For more info see
– http://docs.oracle.com/database/121/CNCPT/tablecls.htm#CNCPT88821
– or search on Ask Tom about external tables. You’ll be surprised 🙂