This scenario describes a classic cascading or dependent data relationship. The best practice in Pega is to use separate, dedicated data pages for each distinct data entity. A list-structure data page should be created to populate the top-level Categories. A second, parameterized list-structure data page should be created for Sub-categories. This Sub-category data page accepts the selected Category ID as a parameter to filter and retrieve only the relevant sub-categories from the database. This approach is modular, reusable, and aligns with Pega's data virtualization principles for optimal performance and maintainability.

A: Using a single, complex data page for both entities violates the single responsibility principle, making it less reusable, harder to maintain, and less performant than two dedicated data pages.

B: This option is incomplete as it fails to specify a data page for loading the initial Category list, which is a critical first step and a Pega best practice.

D: This option only addresses retrieving data after a Sub-category is selected. It completely ignores the primary requirement of how to populate the Category and Sub-category selection lists.

1. Pega Documentation

"Configuring a cascading control": This document explicitly outlines the correct pattern. It states

"To configure a cascading control

you create two controls and source them with two separate data pages. The first data page retrieves a list of values for the first control. The second data page is parameterized to retrieve a filtered list of values for the second control based on the value of the first control." This directly supports option C.

Source: Pega Community / Pega Platform 8.8 Documentation

"Configuring a cascading control".

2. Pega Documentation

"Creating a data page": The documentation on creating data pages emphasizes their role in separating data retrieval logic from the UI. It details the use of parameters to make data pages context-aware

which is the core mechanism for the Sub-category data page.

Source: Pega Community / Pega Platform 8.8 Documentation

"Creating a data page"

Section: "Data page parameters".

3. Pega Academy

Lead System Architect (LSA) Courseware

"Data Modeling" Module: The LSA curriculum stresses the importance of creating a clean

logical

and reusable data model. The principle of creating distinct data pages for distinct business objects (like Category and Sub-category) is a fundamental concept for building scalable and maintainable applications.

Source: Pega Academy

Lead System Architect 8.8

"Data and Integration" Mission

"Data Pages" Module.