In order to install a UNICODE-enabled database, the database parameter _UNICODE must be set to YES.
Note that you cannot change the database parameter _UNICODE once it has been set.
You can use the Database Manager to set the database parameter _UNICODE when you install the database instance.
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1. Start the Database Wizard.
2. Perform the first five installation steps.
3. In step 6 (Parameters), choose Extended.
4. Set the _UNICODE parameter to YES.
5. Continue with the installation.
See also: Database Manager GUI: SAP DB 7.4, section Creating or Initializing a New Database Instance
A script with configuration information for the database instance contains, among other things, lines for definition of the database parameters. You must insert the following line at this point:
param_put _UNICODE YES
See also: Database Manager CLI: SAP DB 7.4, Changing the Value of a Database Parameter