Since 12c csscan and csalter is not supported anymore see here. Therefore the Database Migration Assistant (DMU) has to be used right now. DMU is an external tool with is not shipped with the database software. This tool is suitable for UNICODE migrations (UTF8 or AL32UTF8) only.
So our first step is to download the software
- Link to download Database Migration Assistant for Unicode (DMU) here
- This is a java tool like sqlpdeveloper and need a jdk here.
After first start, there may be a warning due to the java 7 version, just ignore it.
Notice: Only the convert of a Non-CDB is supported by this tool, otherwise you get an error like this:
1. Preparing Database for convert
1.1 Create repository
1.2 Choose character set you want to migrate to
1.2 Choose tablespace where you want to store the migration repository. This does’t need much space so SYSAUX is possible.
1.3 Finish this
2. Scan database data
Like csscan you have to fill your migration repository with data to get what should be converted:
2.1 Choose parameters to start scan
2.2 Choose data you want to scan
2.3 Choose action for scan and start it
2.4 Here an example output of the scanning process
3. Start convertion of the database
3.1 Make sure that you have a database backup!
3.2 Start convert wizard
3.3 Check scan result timestamp is ok
3.4 If not have done right now, than take a backup before start
3.4 Scan wirzard will start now
3.5 Choose conversion parameters
3.6 Check details and start process
3.7 Here an example output of the conversion process
4. Uninstall migration repository
If the migration was successful you can deinstall the migration repository
Overall finished. Now your database has been migrated to UNICODE.