SYSDBA and SYSOPER
The following operations are authorized by the SYSDBA and SYSOPER system privileges:
| System Privilege | Operations Authorized |
|---|---|
| SYSDBA |
Effectively, this system privilege allows a user to connect as user SYS. |
| SYSOPER |
This privilege allows a user to perform basic operational tasks, but without the ability to look at user data. |
The manner in which you are authorized to use these privileges depends upon the method of authentication that you use.
When you connect with SYSDBA or SYSOPER privileges, you connect with a default schema, not with the schema that is generally associated with your username. For SYSDBA this schema is SYS; for SYSOPER the schema is PUBLIC.
OSDBA and OSOPER
Membership in one of two special operating system groups enables a DBA to authenticate to the database through the operating system rather than with a database user name and password. This is known as operating system authentication. These operating system groups are generically referred to as OSDBA and OSOPER. The groups are created and assigned specific names as part of the database installation process. The default names vary depending upon your operating system, and are listed in the following table:
| Operating System Group | UNIX User Group | Windows User Group |
|---|---|---|
| OSDBA | dba | ORA_DBA |
| OSOPER | oper | ORA_OPER |
Oracle Universal Installer uses these default names, but you can override them. One reason to override them is if you have multiple instances running on the same host computer. If each instance is to have a different person as the principal DBA, you can improve the security of each instance by creating a different OSDBA group for each instance. For example, for two instances on the same host, the OSDBA group for the first instance could be named dba1, and OSDBA for the second instance could be named dba2. The first DBA would be a member of dba1 only, and the second DBA would be a member of dba2 only. Thus, when using operating system authentication, each DBA would be able to connect only to his assigned instance.
Membership in the OSDBA or OSOPER group affects your connection to the database in the following ways:
-
If you are a member of the OSDBA group and you specify AS SYSDBA when you connect to the database, then you connect to the database with the SYSDBA system privilege.
-
If you are a member of the OSOPER group and you specify AS SYSOPER when you connect to the database, then you connect to the database with the SYSOPER system privilege.
-
If you are not a member of either of these operating system groups and you attempt to connect as SYSDBA or SYSOPER, the CONNECT command fails.
See Also:
Your operating system specific Oracle documentation for information about creating the OSDBA and OSOPER groups
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