Call now: 252-767-6166  
Oracle Training Oracle Support Development Oracle Apps

 E-mail Us
 Oracle Articles
New Oracle Articles

 Oracle Training
 Oracle Tips

 Oracle Forum
 Class Catalog

 Remote DBA
 Oracle Tuning
 Emergency 911
 RAC Support
 Apps Support
 Oracle Support

 SQL Tuning

 Oracle UNIX
 Oracle Linux
 Remote s
 Remote plans
 Application Server

 Oracle Forms
 Oracle Portal
 App Upgrades
 SQL Server
 Oracle Concepts
 Software Support

 Remote S


 Consulting Staff
 Consulting Prices
 Help Wanted!


 Oracle Posters
 Oracle Books

 Oracle Scripts

Don Burleson Blog 







ORA-30657 External Table Tips

Expert Oracle Database Tips by Donald BurlesonApril 4, 2015


Question:  I am trying to insert into an external table and I get the ORA-30657 error.  

What are ways to populate an external table?

Answer:  External tables are usually loaded from external sources such as spreadsheet data (csv format) or rows that are punched into a flat file in column delimited format.  

Limitations on Oracle External Tables  

In Oracle, external tables have several limitations, including:

  •  No support for DML. Oracle external tables are read-only, but the base data can be edited in any text editor.

  •  Poor response for high-volume queries.

Oracle external tables have a processing overhead and are not suitable for large tables.  

You can also use Oracle utilities such as utl_file to write to an external file, which is mapped to an external table.  

The oerr utility shows this for the ORA-30657 error:

ORA-30657:  Operation not supported on external organized table  

Cause: User attempted on operation on an external table which is not supported.  

ction: Don't do that!

See these related notes on external tables:


Get the Complete
Oracle SQL Tuning Information 

The landmark book "Advanced Oracle SQL Tuning  The Definitive Reference"  is filled with valuable information on Oracle SQL Tuning. This book includes scripts and tools to hypercharge Oracle 11g performance and you can buy it for 30% off directly from the publisher.



Burleson is the American Team

Note: This Oracle documentation was created as a support and Oracle training reference for use by our DBA performance tuning consulting professionals.  Feel free to ask questions on our Oracle forum.

Verify experience! Anyone considering using the services of an Oracle support expert should independently investigate their credentials and experience, and not rely on advertisements and self-proclaimed expertise. All legitimate Oracle experts publish their Oracle qualifications.

Errata?  Oracle technology is changing and we strive to update our BC Oracle support information.  If you find an error or have a suggestion for improving our content, we would appreciate your feedback.  Just  e-mail:  

and include the URL for the page.


Burleson Consulting

The Oracle of Database Support

Oracle Performance Tuning

Remote DBA Services


Copyright © 1996 -  2017

All rights reserved by Burleson

Oracle ® is the registered trademark of Oracle Corporation.

Remote Emergency Support provided by Conversational



Oracle Training at Sea
oracle dba poster

Follow us on Twitter 
Oracle performance tuning software 
Oracle Linux poster