The SDB 12.5 delivered instance must be created using SDBSetupWizard.exe. This will act as the source database for the merge process. For instructions on creating the delivered instance of the SDB, see Create the SDB Database using the SDB Setup Wizard.
If multiple Oracle homes exist on the DB server, the Oracle 19c home must be available before other Oracle homes in the path environmental variable.
Migration to SDB 12.5 is irreversible, so a full database backup is strongly recommended
before starting the migration process.