How Delta Publishing Works

Enable Delta Publishing

To enable delta publishing for a configuration:

1. Open the export configuration.

2. Locate the Options in General tab.

3. Select Publish changes only (delta mode) checkbox.

   

4. Save the configuration.

Publishing Behaviour

When a publish run is started with Delta mode enabled, the gateway applies the following logic for each element:

5. Locate the UDA. The gateway checks whether :GATLASTPUBLISHTIMES is present on the element or on its nearest ancestor element.

   1. If the UDA is not found on the element or any of its ancestors, the element is not published and a warning is shown. See Missing UDA Warning.

6. Check for an existing record for this configuration. The gateway looks for a string in the UDA array that matches the GUID of the current configuration.

   2. If no matching record is found, the element has never been published with this configuration. The gateway publishes the element.

   3. If a matching record is found, the gateway reads the stored last publish date and time and proceeds to step 3.

7. Compare the configuration modification date. The gateway checks whether the configuration itself was modified after the last publish date and time stored in the UDA.

   4. If the configuration was modified after the last publish, the element is always published, regardless of whether the element data changed.

8. Compare element changes. If the configuration has not been modified since the last publish, the gateway checks whether the element data has changed since the stored last publish date and time.

   5. If the element has changed, it is published.

   6. If the element has not changed, it is skipped.

9. Update the UDA. After a successful publish run (with no errors), the gateway updates :GATLASTPUBLISHTIMES for each published element, recording the configuration GUID and the current UTC date and time.

Summary of Publishing Decisions

Missing UDA Warning

If an element is processed by a delta-enabled configuration and the :GATLASTPUBLISHTIMES UDA cannot be found on the element or any of its ancestors, the element is excluded from the publish output and a warning message is displayed. To resolve this, ask your project administrator to add the :GATLASTPUBLISHTIMES UDA to the appropriate element types as described in Prerequisites - Setting Up the UDA.