Before Oracle 19c, we can connect to the database as the user "sys" without giving "as sysdba" if the parameter O7_DICTIONARY_ACCESS is set to TRUE. If this parameter is set to FALSE, you won't connect to the database as the user "sys" without giving "as sysdba". You will get the ORA-280009 if you do so. … Continue reading Oracle 19c — ORA-28009: connection as SYS should be as SYSDBA or SYSOPER →