Differences between sys and system User Permissions in Oracle

Differences between Oraclesys and system users, sysdba and sysoper system permissions, and sysdba and dba roles

Differences between Oracle sys and system users, sysdba and sysoper system permissions, and sysdba and dba roles

Differences between Oracle sys and system users, sysdba and sysoper system permissions, and sysdba and dba roles

Differences between sys and system users

1) The most important difference is that the importance of stored data is different.

Base tables and views of all oracle data dictionaries in sys are stored in sys users. These base tables and views are crucial for oracle operation and are maintained by the database, no user can change it manually. Sys users have the role or permissions such as dba, sysdba, and sysoper, and are the users with the highest oracle permissions.

The system user is used to store the second-level internal data, such as the Management Information of some features or tools of oracle. System users have common dba role permissions.

2) The second difference is that permissions are different.

System users can only log on to em as normal, unless you have granted sysdba system permissions or syspoer system permissions to them.
The sys user has system permissions of "SYSDBA" or "SYSOPER". You can only use these two identities to log on to em, but cannot use normal.

Log on to Oracle as a sys user and run select * from V _ $ PWFILE_USERS. Users with sysdba permissions can be queried, for example:

SQL> select * from V _ $ PWFILE_USERS;
USERNAME SYSDBA SYSOPER
SYS TRUE

Differences between Sysdba and sysoper system Permissions

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.

Sysdba and sysoper belong to system privilege, also known as administrative privilege. The specific permissions of sysdba and sysoper at the system management level such as enabling or disabling a database can be viewed in the following table:

System Permissions

Sysdba

Sysoper

Differences

Startup (start database)

Startup

Shutdown (shut down the database)

Shutdown

Alter database open/mount/backup

Alter database open/mount/backup

Change Character Set

None

Create database)

None

Drop database)

None

Create spfile

Create spfile

Alter database archivelog (archive logs)

Alter database archivelog

Alter database recover (recover database)

Only full recovery is allowed, and incomplete recovery cannot be performed.

Have restricted session (session Restriction) Permissions

Restricted session permission

Allows users to connect as sys users

Some basic operations can be performed, but user data cannot be viewed.

After logon, the user is sys.

After logon, the user is public.