External Tables Overview and Usage (Doc ID 150740.1)

Purpose

This note explains the purpose and usage of external tables.
External tables is introduced in version 9i of Oracle.

Scope

For DBAs who need to store data outside the database and manipulate them inside the database without requiring to load the data in the database.

This feature becomes interesting in a data warehouse environment during the ETL process (Extraction Transformation Loading), as a complement to SQL*Loader: it prevents temporary tables to be created during the Extraction and Transformation phases, thus reducing space allocated and risk of abnormal termination during the whole process. It can be used in place of SQL*Loader when the external data volume is large and used only once.

Details

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