Pega Keyed data page

Keyed page access in pega

Pre-loads the data from the original data source and returns matching instances by using one or more keys. The keyed data page is the best implementation when there are frequent unique queries before the information becomes stale. Keyed data page configuration is only applicable to List type data pages and "Read-Only" mode.

We can configure the keyed page access by selecting the check box.

When selected, we need to pass a key in the Pagelist keys section. Optionally we can select "Allow multiple pages per key" this allows each key to return multiple matching results. If not selected and have multiple matches key reruns the first matching page.

We have a "+ Add key" option, which is called "Multiple keys per data page" we can define multiple keys pega will return a result(s) based on the matching of the specified keys.

How to reference the keyed data page in pega?

Only properties can reference keyed data pages. Both property and data pages should be in the same class context.

Please see the RequestTypeTest page property, we have 3 options in the Data Access section.

1.         Manual
2.         Refer to a data page
3.         Copy data from a data page

we can achieve keyed access configuration with "Refer to a data page" and "Copy data from a data page" options.

1.Refer to a data page:

A new data page will be created on the first reference of the "RequestTypeTest" page property, data will not be stored in page property, but only contains a reference to the data page.

Below is the clipboard structure how it looks:

Pega calls this reference pattern a System of Records (SoR). This pattern allows access to data which is stored in other system or application. The application always references the system of record, so the data is always current. Pega ensures data accessed by the application is always fresh and current.

Refresh strategy in SoR pattern:

The data page will reload as per the refreshed strategy defined on the data page. Property always has the current version of the refreshed data page's reference. Whenever a data page parameter is updated, a new data page is created and the property then points to the new page. 

2. Copy data from a data page

A new data page will be created on the first reference of the "RequestTypeTest" page property and data will be copied to the page property. Data will not be refreshed until the parameter value changed.

Please see the clipboard structure below:

Pega calls this as "Snapshot pattern" - system copies matched snapshot record from data page to page property.

Refresh strategy Snapshot pattern:

Once we copy data from a data page, the data is stored in the page property. The data page is not accessed again until parameter changes. When the parameter changes, a new data page is created and effected data is copied to the property and overwrites the current data.

3. Manual - Reference pattern

We normally use this in UI controls to populate dynamic data on to drop down or auto-populate controls.

Refresh strategy:

Data page reloads according to the refreshed strategy specified on the data page, UI control always points to the new version of the data page.

Read Data pages complete understanding

Read parameterized data page in pega