ORA-03893
Shard DDL cannot be executed as SYS because the following shards need to be upgraded to at least Oracle Database 21c: string.
Cause
An attempt was made to execute shard DDL as user SYS. This is insecure unless it can be encrypted.
Action
Either execute the DDL as another user, or upgrade the listed shards to at least Oracle Database 21c and update them to support encryption.