Oracle Concepts - Setting Roles Oracle Tips by Burleson Consulting

Setting Roles

When a user is created, the default for active roles is set to ALL. The default ALL means that all the roles granted to a user are active. The DBA can change the default with an ALTER USER command. A user can enable multiple roles at one time and use the SET ROLE command to switch between roles or activate all roles with the command SET ROLE ALL. The SET ROLE ALL command will not work if any of the roles assigned to that user requires either a password or operating system authentication. The command line syntax for setting roles is shown in Figure 13.

Figure 7.13 Syntax for setting roles.

Users can look at the SESSION_ROLES view to find the roles that are currently enabled for them. Users can look at SESSION_PRIVS view to see the privileges available to their session.

If you determine that all control of roles will be at the operating system level, you can set the database initialization parameter OS_ROLES equal to TRUE. All roles must still be created first in the database. Any grants you previously made using the database command line or Server Manager are still listed in the data dictionary, but they cannot be used and are not in effect. If the use of roles is determined at the operating system level, the multithreaded server option cannot be used.

You can use the MAX_ENABLED_ROLES parameter in the database initialization file to set the number of roles that you will allow any user to have enabled at one time.

Special Roles

If you intend for administration level users to use OS authentication create the following two roles when you install the Oracle executables:

* OSOPER

* OSDBA

Oracle creates the following three roles when you create the database:

* CONNECT

* RESOURCE

* DBA

When you execute the sql.bsq script, the following two roles are created:

* EXP_FULL_DATABASE

* IMP_FULL_DATABASE

When recovery manager is created, the following five roles are created:

* SELECT_CATALOG_ROLE

* EXECUTE_CATALOG_ROLE

* DELETE_CATALOG_ROLE

* RECOVER_CATALOG_ROLE

* RECOVERY_CATALOG_OWNER

FINALLY, WITH THE ADDITION OF THE ADVANCED QUEUING OPTION, THE FOLLOWING TWO ROLES ARE CREATED

* AQ_ADMINISTRATOR_ROLE

* AQ_USER_ROLE

In the following section, I’ll explain these special roles and how they are used for database maintenance.

OSOPER And OSDBA

The OSOPER and OSDBA roles are created at the operating system level when Oracle is installed. They cannot be granted. The OSOPER and OSDBA roles are needed to perform database operations when the database is not mounted and therefore the data dictionary is not accessible. It is the OSOPER and OSDBA roles that are used when you use CONNECT INTERNAL to connect to the database using Server Manager.

The OSOPER role can perform the following database management commands:

* STARTUP

* SHUTDOWN

* ALTER DATABASE OPEN/MOUNT

* ALTER DATABASE BACKUP CONTROLFILE

* ALTER TABLESPACE BEGIN/END BACKUP

* ARCHIVE LOG

* RECOVER

The OSDBA role has  the OSOPER role.  In addition, the OSDBA role has the WITH ADMIN OPTION to allow it to grant system privileges to other users.  This is the role that is used to create the database and for time-based recovery processes. Both the OSOPER and OSDBA roles include the RESTRICTED SESSION system privilege.

If you intend to allow remote users to connect internal, you need to set the REMOTE_LOGIN_PASSWORDFILE option in your database parameter file to either EXCLUSIVE or SHARED.  The user will then connect in server manager with the  AS SYSDBA or  AS SYSOPER clause at the end of the CONNECT command (CONNECT SYS AS SYSDBA).  The privileges assigned to SYSDBA correspond to those for OSDBA.  The privileges assigned to SYSOPER correspond to OSOPER.  The operating system verifies the password provided using an external operating system file.  This external file is generated using the ORAPWD utility.  When the password for the INTERNAL or SYS accounts are changed with the ALTER USER command, the changes are mapped to the operating system password file. 

CONNECT, RESOURCE, And DBA Roles

The CONNECT, RESOURCE, and DBA roles are predefined roles that are available for backward compatibility. These are created by Oracle when the database is created. When you create a user with Oracle Enterprise Manager, the CONNECT role is automatically granted to that user.

The following system privileges are granted to the CONNECT role:

* ALTER SESSION

* CREATE CLUSTER

* CREATE DATABASE LINK

* CREATE SEQUENCE

* CREATE SESSION

* CREATE SYNONYM

* CREATE TABLE

* CREATE VIEW

When you grant a user the RESOURCE role, that user is granted the UNLIMITED TABLESPACE system privilege as well. The following system privileges are granted to the RESOURCE role:

* CREATE CLUSTER

* CREATE PROCEDURE

* CREATE SEQUENCE

* CREATE TABLE

* CREATE TRIGGER

* CREATE TYPE

The DBA role includes all system privileges (95 separate grants), the capability to grant those system privileges to others, and UNLIMITED TABLESPACE is granted in the same way as with the RESOURCE role. If the EXP_FULL_DATABASE and IMP_FULL_DATABASE roles have been created, they are granted implicitly with the DBA role as are the DELETE, EXECUTE and SELECT_CATALOG_ROLE roles.

You can grant additional privileges to or revoke privileges from the CONNECT, RESOURCE, and DBA roles just as you would any other role that you created.

This is an excerpt from the eBook "Oracle DBA made Simple".

For more details on Oracle database administration, see the "Easy Oracle Jumpstart" by Robert Freeman and Steve Karam.  It’s only $19.95 when you buy it directly from the publisher here.