Dependent Privileges
Definition:
Dependent privileges are permissions that are influenced or contingent upon privileges associated with other database objects or actions. These privileges can affect how permissions are granted or revoked based on the relationship between objects in the database.
Examples of Dependent Privileges:
Privileges on Tables and Indexes:
When a user has the privilege to insert data into a table, they might also implicitly need privileges to create indexes on that table, depending on the database system’s configuration. For instance, creating an index might require ALTER privileges on the table.
Privileges on Views:
If a user has SELECT privileges on a view, they must also have the necessary privileges on the underlying tables that make up that view. If privileges on these tables are altered or revoked, it will impact access to the view.
Privileges on Stored Procedures:
Stored procedures might call other procedures or access tables and views. The privileges needed to execute a stored procedure might depend on the privileges required for the objects that the procedure interacts with.
Managing Dependent Privileges:
Managing Privileges on Views:
-- Grant SELECT privilege on a view GRANT SELECT ON view_name TO user_name; -- Ensure the user also has necessary privileges on the underlying tables of the view GRANT SELECT ON underlying_table1 TO user_name; GRANT SELECT ON underlying_table2 TO user_name;
Managing Privileges on Indexes:
-- Grant ALTER privilege on a table, which may include the ability to create indexes GRANT ALTER ON table_name TO user_name;
Managing Privileges on Stored Procedures:
-- Grant EXECUTE privilege on a stored procedure GRANT EXECUTE ON procedure_name TO user_name; -- Ensure the user also has necessary privileges on the objects used by the procedure GRANT SELECT ON table_name TO user_name;
Implications of Dependent Privileges:
Privilege Propagation:
Privileges on dependent objects can affect access and management of related objects. For example, revoking a privilege on a table may impact access to views or procedures that use this table.
Management and Auditing:
Effective privilege management involves auditing dependent privileges to ensure they are configured correctly and that users have the necessary rights on all related objects.
Security:
Proper management of dependent privileges is crucial to avoid security risks. Incorrectly configured dependent privileges can lead to unauthorized access or failures in executing actions.
Complexity in Management:
Managing dependent privileges can be complex, particularly when there are chains of dependencies among multiple objects. Understanding how privilege changes will affect the entire system is important.
Summary:
Dependent Privileges: These are permissions that are influenced by the rights granted on other objects or actions within a database.
Examples: Privileges on tables, views, indexes, and stored procedures can have dependent effects on other objects.
Management: Involves granting and revoking privileges appropriately to maintain correct access and ensure security.
Implications: Understanding dependencies is crucial for effective and secure privilege management in a database.