In Oracle, user permissions are a collection of database functions and operations authorized to users. In order to ensure the security of the database, administrators need to review the permissions that have been assigned to users to ensure that users can only perform the operations they need and are not given other unnecessary permissions.
Querying user permissions is a common task, and administrators can use different methods provided by Oracle to view user permissions. Here are some commonly used query methods.
Method 1: Query user authorization
You can use the system view authorization table to query the permissions of a specific user. For example, you can use the following query statement to find the permissions of the user named "exampleuser":
SELECT * FROM USER_SYS_PRIVS WHERE GRANTEE = 'exampleuser';
This query will display the list of system permissions granted by the user, such as creating tables, creating triggers, etc.
Method 2: Query Role Authorization
You can use the following query command to view the permissions of users with specific roles:
SELECT * FROM ROLE_SYS_PRIVS WHERE ROLE = 'example_role';
This query will display users with this role List of granted system permissions. If you need to view the permissions of all roles, you can replace the query statement with the following statement:
SELECT * FROM ROLE_SYS_PRIVS;
Method 3: Query object authorization
You can use the ALL_TAB_PRIVS system view to query object-level permissions. For example, the following query returns a list of all table-level and view-level permissions that a given user has:
SELECT * FROM ALL_TAB_PRIVS WHERE GRANTEE = 'exampleuser';
If you need to query the permissions of a specific user on a specific table, you can use the following query command:
SELECT * FROM ALL_TAB_PRIVS WHERE GRANTEE = 'exampleuser' AND TABLE_NAME = 'example_table';
This query will return a list of permissions of a specific user on the "example_table" table.
Method 4: Query Role Authorization and Default Role
Oracle also supports the concepts of role authorization and default role. Default roles are automatically assigned when users log in, while role authorization grants permissions to roles rather than specific users.
You can view the default roles and role authorizations using the following query command:
SELECT * FROM DBA_ROLE_PRIVS WHERE GRANTEE = 'exampleuser';
This query will return a list of the default roles and role authorizations assigned to a specific user.
Summary
Understanding how to query user permissions is a necessary task for Oracle database administrators to manage user permissions and protect database data security. Administrators can use different query methods to obtain permission information owned by users and roles in order to monitor and manage user access permissions. In addition to the above methods, Oracle also provides some other tools and views to manage and query user permissions, such as DBA_SYS_PRIVS, SESSION_PRIVS, etc.
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