ORA-28009: connection as SYS should be as SYSDBA or SYSOPER

Question

Porque este erro acontece?
Acontece porque o parâmetro O7_DICTIONARY_ACCESSIBILITY está configurado como FALSE.
Agora vamos ao que interessa, como resolver:
Conecte-se como SYSDBA
SQL> conn / as sysdba
Connected
Agora vamos configurar aquele parâmetro para TRUE
SQL> ALTER SYSTEM SET O7_DICTIONARY_ACCESSIBILITY=TRUE scope=spfile;
System altered.
Agora você pode fechar o DB e abrir novamente, e logar-se como SYS ( SQL> connect sys/passwd@sv ).

Answer 1

http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:940042518290
"My recommendation would be to leave the the O7_DICTIONARY_ACCESSIBILITY set to false and
change scripts that connect as SYS to connect as some other user. Using the SYS account
should be avoided in any case -- you should never use it to create objects, cannot use it
to create triggers and some commands (for example "set transaction read only") don't even
work when connected as SYS.
Consider SYS to be a special account that you never need to use anymore."