Differences between normal, sysdba, and sysoper login to Oracle

Differences between sys and system users
[System] You can only log on to Em as normal.
[Sys] a user has the "sysdba" or "sysoper" permissions. the user can only log on to Em using these two identities and cannot use normal.
"Sysoper" permission, that is, database operator permission, includes:
Open Database Server close Database Server
Backup database recovery database
Log archiving session restrictions
The "sysdba" permission, that is, the database administrator permission, includes:
Open Database Server close Database Server
Backup database recovery database
Log archiving session restrictions
Manage functions to create databases

What are the differences between normal, sysdba, and sysoper?
Normal is a common user
For the other two, you can check their permissions.
Sysdba has the highest system Permissions
Sysoper is mainly used to start and close databases. After logging on to sysoper, the user is public.
After logging on to sysdba, It is sys.

SQL> Conn/As sysdba
Connected.
SQL> grant sysoper to test;

Authorization successful.

SQL> conn test/test as sysoper;
Connected.
SQL> show user
The user is "public"
SQL> conn test/test as sysdba
Connected.
SQL> show user
User is "sys"
SQL>

 

 

Differences between dBA and sysdba
What are the differences between dBA and sysdba system roles?
Before explaining this, I need to talk about the Oracle service creation process.
· Create an instance
· Start an instance
· Create a database (system tablespace is required)
Startup Process
· Instance startup
· Load databases
· Open a database

Sysdba manages Oracle instances and does not rely on the full startup of the entire database,
As long as the instance is started, it already exists. log in as sysdba, load the database, and open the database
The DBA role has a foundation only when the database is opened or the entire database is fully started!