Book Image

Oracle 10g/11g Data and Database Management Utilities

Book Image

Oracle 10g/11g Data and Database Management Utilities

Overview of this book

Does your database look complicated? Are you finding it difficult to interact with it? Database interaction is a part of the daily routine for all database professionals. Using Oracle Utilities the user can benefit from improved maintenance windows, optimized backups, faster data transfers, and more reliable security and in general can do more with the same time and resources.
Table of Contents (18 chapters)
Oracle 10g/11g Data and Database Management Utilities
Credits
About the Author
About the Reviewer
Preface

The External Table basics


An External Table is basically a file that resides on the server side, as a regular flat file or as a data pump formatted file. The External Table is not a table itself; it is an external file with an Oracle format and its physical location. This feature first appeared back in Oracle 9i Release 1 and it was intended as a way of enhancing the ETL process by reading an external flat file as if it was a regular Oracle table. On its initial release it was only possible to create read-only External Tables, but, starting with 10g—it is possible to unload data to External Tables too.

In previous 10g Releases there was only the SQL*Loader driver could be used to read the External Table, but from 10g onwards it is now possible to load the table by means of the data pump driver. The kind of driver that will be used to read the External Table is defined at creation time. In the case of ORACLE_LOADER it is the same driver used by SQL*Loader. The flat files are loaded in the...