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Database Migration Assistant for Unicode (DMU) in Oracle Database 12c Release 1 (12.1)

The Database Migration Assistant for Unicode (DMU) is listed as a 12c new feature, but it is actually a separate tool that supports a number of different database versions.

Related articles.

Download

Version 1.2 of the DMU is shipped with the 12c database. You can see it by running the following commands.

$ cd $ORACLE_HOME/dmu
$ sh dmu.sh

Oracle recommend you always download the latest release before starting a migration. At the time of writing, version 2.0 is available at OTN.

Once you've downloaded it, it can be unzipped and run from anywhere, but I prefer to unzip it under a new directory in the ORACLE_HOME.

$ mkdir $ORACLE_HOME/dmu-2.0
$ cd $ORACLE_HOME/dmu-2.0
$ unzip /tmp/dmu-2.0.zip

Prepare

Make sure the SYS.DBMS_DUMA_INTERNAL package is installed.

$ sqlplus / as sysdba

SQL> @?/rdbms/admin/prvtdumi.plb

Library created.


Package created.

No errors.

Package body created.

No errors.
SQL>

It's a good idea to create a separate tablespace for the repository, rather than using the SYSAUX tablespace.

SQL> CREATE TABLESPACE unicode_repo DATAFILE SIZE 100M AUTOEXTEND ON NEXT 10M;

If you are running against a database version prior to 11.2.0.3, you will probably need to patch your database. You can see the compatibility matrix here and the patch here.

Migrate

During the migration process the Migration Status tab normally tells you the next step to take, and provides links to jump to the next step so you don't have to use the menu. In this article I chose to use the menus directly, but if you don't like that, always click back on the Migration Status tab between steps to see what you should do next.

We are now ready to start the migration.

$ export JAVA_HOME=$ORACLE_HOME/jdk
$ cd $ORACLE_HOME/dmu-2.0/dmu
$ sh dmu.sh

Right-click on the "Databases" node in the Navigator pane and select the "New Database Connection" option from the popup menu.

Database Migration Assistant for Unicode (DMU)

Enter the connection details and click the "Test Connection" button. Once you get a successful test, click the "Save" button to return to the previous screen.

DMU : Create Database Connection

When you return to the previous screen, expand the new connection node in the tree to start the Repository Configuration Wizard. Accept the "Install the repository in migration mode" option by clicking the "Next" button.

DMU : Repository Configuration Wizard - Select Task

Accept the "ALT32UTF8" option by clicking the "Next" button.

DMU : Repository Configuration Wizard - Task Details

Select the tablespace to hold the repository, then click the "Finish" button. Wait for the repository to be created, then click the "OK" button on the subsequent message box.

DMU : Repository Configuration Wizard - Select Tablespace

Right-click on the database connection and select the "Scan Database" option from the popup menu.

DMU : Scan Database

Click the "Next" button.

DMU : Scan Wizard - Welcome

Alter any parameters as required, then click the "Next" button.

DMU : Scan Wizard - Set Parameters

Select the objects to scan, then click the "Next" button.

DMU : Scan Wizard - Select Scan Objects

Check the scan details, then click the "Finish" button.

DMU : Scan Wizard - Scan Details

Wait while the scan takes place. Once complete, click the "OK" button on the message box.

DMU : Scan Wizard - Scan Progress

Right-click on the database connection and select the "Database Scan Report" option from the popup menu.

DMU : Database Scan Report

Check the report for possible problems.

DMU : Database Scan Report

Right-click on the database connection and select the "Bulk Cleansing" option from the popup menu.

DMU : Bulk Cleansing

Click the "Next" button.

DMU : Bulk Cleansing Wizard - Welcome

Accept the "Migrate to character length semantics" option by clicking the "Next" button.

DMU : Bulk Cleansing Wizard - Action Selection

Decide if you want column changes to happen immediately, or during the conversion. Click the "Next" button.

DMU : Bulk Cleansing Wizard - Parameters

Select the objects to be converted, then click the "Next" button.

DMU : Bulk Cleansing Wizard - Object Selection

Click the "Finish" button. Wait for the bulk cleansing to complete, then click the "OK" button on the resulting message box.

DMU : Bulk Cleansing Wizard - Details

Check the results of the bulk cleansing.

DMU : Bulk Cleansing Wizard - Progress

Right-click on the database connection and select the "Convert Database" option from the popup menu.

DMU : Convert Database

Click the "Convert" button.

DMU : Convert Database - Summary

Click the "Yes" button to start the conversion.

DMU : Convert Database - Ready for Conversion

The conversion will initiate the Scan Wizard again. Accept all the defaults by clicking the "Next" and "Finish" buttons where appropriate. Once the "Finish" button is clicked, the conversion will start. Wait for it to complete, then click the "OK" button on the final message box. You are presented with a screen showing you the outcome of the conversion.

DMU : Convert Database - Conversion Steps

The Migration Status tab also shows the conversion is complete.

DMU : Migration Status

Right-click on the database connection and select the "Configure DMU Repository" option from the popup menu.

DMU : Configure DMU Repository

Select the "uninstall the repository" option and click the "Next" button.

DMU : Repository Configuration Wizard - Select Task

Click the "Finish" button. Once complete, click on the "OK" button on the message box.

DMU : Repository Configuration Wizard - Uninstall Repository

Exit the Database Migration Assistant for Unicode (DMU) using the "File > Exit" menu option.

The conversion is complete.

Tidy Up

If you created a new tablespace for the migration, you can drop it now.

sqlplus / as sysdba

SQL> DROP TABLESPACE unicode_repo INCLUDING CONTENTS AND DATAFILES;

For more information see:

Hope this helps. Regards Tim...

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