I just created a user, create user lisi identified by lisi; when I use sqlplus login:
cmd -> sqlplus lisi / lisi entrance -> lisi lisi as sysdba and then went in, so only the question.
Then I entered the administrator, the user will be deleted lisi
cmd -> sqlplus lisi / lisi entrance -> lisi lisi as sysdba and then went in, I doubt it deeper.
They were three answers:
For windows operating system, after Oracle database installation automatically installs a user group named ORA_DBA in the operating system, as long as the group of users that can
SYSDBA logged in a database and does not validate the SYS password. You can also create a user group named ORA_SID_DBA (SID for the instance name), the user belongs to the user group to be
Have more privileges. This is why you can show or when the system users,
Simply put, oracle sysdba to think you have the following three conditions
1. your oracle password file not been set up; (because oracle does not authenticate the user with sysdba default login)
2. Your identity is based on the operating system administrator login (regardless of who is logged on your computer, as long as the administrator is logged on, oracle recognize as sysdba, you can try to use the guest operating system login account, in that case, oracle you would not recognize as a DBA);
3. You are logged in as sysdba way (as long as you pick up as sysdba, no matter who is in front of you add a username and password, oracle think you are logged in as sysdba, user sys)
When the above three conditions are not met, the user is not logged on your sys, and if you log the user is not authorized to dba, then his authority can only be sure of the ordinary privileges.
It is possible, but then you add as sysdba landing is sysdba, and the user does not matter in front of you, if you create a new user user1, such as create user user1 identfied by 123, then grant him landing sys account the wording after permissions, you can directly conn user1 / 123, this connection is user1, if you conn user1 / 123 as sysdba, you connect or sysdba, and a little user1 relations front are gone.