Oracle SQL Experts: REVOKE FAQS

1. What happens if I revoke a privilege granted to a user through a role?

When you revoke a privilege granted to a user through a role, the user will lose that privilege unless the privilege was granted directly to them as well. If the privilege is granted both directly and through a role, you will need to revoke it from both places.

2. Can I revoke privileges granted to multiple users at once?

Yes, you can revoke privileges from multiple users in a single REVOKE statement. Simply specify the users separated by commas. For example:

· REVOKE SELECT ON employees FROM user1, user2, user3;

3. What does CASCADE CONSTRAINTS do in a REVOKE statement?

The CASCADE CONSTRAINTS clause is used when you want to revoke a privilege on an object that is associated with foreign key constraints. If the privilege is being used in a foreign key relationship, this option ensures that any dependent constraints are dropped automatically when the privilege is revoked.

4. Can I revoke system privileges from a user?

Yes, system privileges (like CREATE SESSION, CREATE TABLE, etc.) can be revoked from a user. For example:

· REVOKE CREATE SESSION FROM user1;

5. Can I revoke a role from a user?

· REVOKE role_name FROM user_name;

6. Can I revoke all privileges from a user on a specific object?

Yes, you can revoke all privileges from a user on a specific object. For example:

· REVOKE ALL PRIVILEGES ON employees FROM user1;

7. Can I revoke privileges from the PUBLIC role?

Yes, you can revoke privileges granted to PUBLIC, which means revoking access from all users. For example:

· REVOKE SELECT ON employees FROM PUBLIC;

8. What happens if I revoke the GRANT OPTION privilege?

If you revoke a privilege that was granted with the GRANT OPTION, the user will no longer be able to grant that privilege to other users. If the privilege was also granted to other users, they will lose it as well.

9. Can I revoke a privilege from a user but keep it for others?

Yes, you can revoke a privilege from a specific user, and other users who have the same privilege will not be affected. This is useful for fine-grained access control. For example:

· REVOKE SELECT ON employees FROM user1;

10. Can I revoke a privilege if the user has dependent objects?

Yes, you can revoke privileges even if there are dependent objects or foreign key relationships. Using CASCADE CONSTRAINTS will drop the dependent constraints automatically.

11. What is the difference between REVOKE and DROP in Oracle?

The REVOKE statement removes a user’s privileges on objects or system resources, while the DROP statement is used to permanently remove an object from the database (such as a table, view, or user).

12. Is it possible to revoke a privilege granted to a user by another user?

Yes, you can revoke a privilege that was granted by another user. However, you need the appropriate administrative privileges (like GRANT OPTION or DBA rights) to do so.

13. How does revoking privileges affect security?

Revoking privileges is a way to tighten security and reduce the risk of unauthorized access to sensitive data or resources. By carefully revoking unnecessary privileges, you ensure that users can only access what they need to perform their tasks.

14. Can I revoke a privilege that was granted to a role?

Yes, you can revoke privileges granted to a role, and this will affect all users who have that role granted to them. For example:

· REVOKE SELECT ON employees FROM sales_role;

15. Can I revoke a privilege granted to a view or stored procedure?

Yes, you can revoke privileges on views or stored procedures, just like you can with tables. For example:

· REVOKE EXECUTE ON my_procedure FROM user1;

16. Can I revoke privileges from a user and still leave the object intact?

Yes, revoking privileges does not delete the object (e.g., table, view, or procedure); it just removes the user's ability to interact with it based on the revoked privilege.

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