Oracle Utilities - Summary

Managing data with External Tables is a means not only for mapping external flat files as regular (but limited) tables inside the database, but also a tool to more efficiently perform administrative tasks such as programmatically processing database log files such as the alert.log or the listener.log files.

It can be used to easily view external XML formatted files from inside the database without actually loading the file to the database. It can also be used as a means of unloading data in temporary external storage to exchange data among different Oracle versions.

This particular feature allows the user to easily build an Oracle Datamart that allows the pre-formatting and summarization of data from the source, enabling it to be directly inserted into the target data warehouse.

The different uses an External Table has allows the user to take full advantage of external flat files and have them loaded to the database in a very easy and convenient way.

There are limitations with External Tables, such as the lack of indexes, the full table scans operations that must be performed even if a single row is to be accessed, the lack of security for the flat files, and the lack of transactional control, but certainly the advantages this concept offers overcome its disadvantages.

The flexibility to manage data in different ways makes it the default choice for data exchange operations.