My Oracle Support Banner

The Database Migration Assistant for Unicode (DMU) Tool (Doc ID 1272374.1)

Last updated on APRIL 14, 2022

Applies to:

Oracle Database Exadata Express Cloud Service - Version N/A and later
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Oracle Database - Standard Edition - Version to [Release 10.2 to 12.1]
Database Migration Assistant for Unicode - Version 1.2 and later
Oracle Database - Enterprise Edition - Version to [Release 12.1]
Information in this document applies to any platform.


Provides Overview, Introduction , Features and Installation steps for DMU (Database Migration Assistant for Unicode) which is used to convert the NLS_CHARACTERSET of an existing database to AL32UTF8 or UTF8.


To customers and engineers who are interested to know about characterset migration to Unicode using DMU and it can also be used to validate data in existing AL32UTF8/UTF8 database.


To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!

In this Document
 1) What is the DMU (Database Migration Assistant for Unicode) tool?
 2) Where to find the tool and the documentation?
 3) Oracle RDBMS version requirements (this is server / database side) for the DMU tool:
 3a) Oracle database Oracle Database 12c, Release 1( and higher
 3b) Oracle database and
 3c) Oracle database and lower ( including 11gR1 and 10g)
 4) DMU client ( User Interface) requirements:
 4a) the server has Oracle 12c installed or an 12c client can be used
 4b) all clients/servers are Oracle Oracle Database 11g, Release 2(11.2.0.x) and lower
 5) Is DMU supported / how to get help?
 6) How to take an html export of the scan result using the "with some issues" filter:
 7) How long will a conversion using DMU take?
 8) What about Physical / Logical Standby databases?
 9) What is the "Install in Validation mode" option when installing the DMU repository when connecting to an UTF8 or AL32UTF8 NLS_CHARACTERSET database with the DMU tool?
 10) It's not possible to create the DMU diag package:
 11) Im currently using DMU 2.0,  can I update to DMU 2.1 without starting over?
 12) Can I use Flashback DB while testing/migrating with DMU to go back?
 13) How to convert non-Unicode PDB's to Unicode PDB's?
 14) How to obtain DMU logs
 15) Is there a command line interface for DMU.

My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.