Edit the Attributes of an Existing Authorization Scheme in Oracle APEX

 Editing the attributes of an existing authorization scheme allows you to update the conditions and behaviors that control user access to different parts of your application. This can be essential for fine-tuning security settings based on evolving requirements.

Steps to Edit the Attributes of an Existing Authorization Scheme

1. From the Workspace home page, click on the App Builder icon.

2. Select the application where you want to modify the authorization scheme.

3. On the Application home page, click on Shared Components.
   This opens the Shared Components page.

4. Under the Security section, select Authorization Schemes.
   The Authorization Schemes page appears. By default, the schemes are displayed as icons. You can use the search bar at the top of the page to filter and customize how the schemes are displayed.

5. Click on the authorization scheme you wish to edit.

6. Edit the necessary attributes of the scheme, such as: 

• Authorization Scheme Type (e.g., SQL query, PL/SQL function).

• Authorization Logic (modify the SQL query or PL/SQL function).

• Error Message (customize the message shown when authorization fails).
  For more details, refer to field-level help within the page.

7. Once you've made the necessary changes, click Apply Changes to save your edits.

Changing the Evaluation Point for an Authorization Scheme

The Evaluation Point attribute controls when an authorization scheme is validated. You can adjust this setting to determine how often the authorization scheme is re-evaluated during a session.

Authorization schemes are generally evaluated when they are first used in a session. The Validate Authorization Scheme attribute allows you to set when and how often re-evaluations occur, based on your application's needs.

Steps to Change the Authorization Scheme Evaluation Point

1. On the Workspace home page, click the App Builder icon.

2. Select the application you want to modify.

3. On the Application home page, click Shared Components.
   This will bring you to the Shared Components page.

4. Under the Security section, click Authorization Schemes.
   The Authorization Schemes page will appear. You can search or filter the schemes using the search bar at the top of the page.

5. Select the authorization scheme you want to modify.

6. Scroll down to the Evaluation Point section and update the Validate Authorization Scheme setting.
   You have several options:

• Once per session: The scheme is evaluated only once per session, and the result is memorized for subsequent requests.

• Once per page view: The scheme is evaluated for each page view, but the memorized result is used if the authorization scheme is referenced more than once on the same page.

• Once per component: The scheme is evaluated once per component on the page, with the result stored in the session for future use on that component.

• Always (No Caching): The authorization scheme will always be evaluated for every request without caching the result.

If you choose Once per session, it is the most efficient option for general use. Consider using another setting if the authorization check depends on factors that change during the session, such as changes in session state or user roles.

7. After making your changes, click Apply Changes to save the updated settings.

By carefully adjusting the evaluation point, you can optimize the performance of your application while ensuring the correct authorization checks are made at the right time.