How do Delta Exports work

To reduce transport time and data volume for big feeds, it is possible to only send the data that has actually been updated. These changes or differences are called deltas.

Exports that use delta files do usually indicate it within their name. The creation of delta files is not depending on a certain destination, some destinations might not support it, though.

Definition of delta: Delta is a way of storing or transmitting data in the form of differences (deltas) between sequential data rather than complete files; more generally this is known as data differencing.

How does that show in the export?

The export identifies each single item by a unique key, which is usually the product identifier (id, GTIN, variant id etc.). During the delta creation the data is compared to the data from the last export and separated into four types: - New: These items are new to the feed - Changed: These items have been in the feed before, but attributes have changed - Deleted: These items are not in the feed anymore (they could be skipped, or removed completely from the platform). - UnchangedThese items have been in the feed before and no attribute has changed

How does that reduce transport time?

There are several scenarios how this might reduce transport time.The most common is to not export unchanged products. If no filename for the unchanged file is given, the file will not be created and exported.Another scenario could be to only export new products, but that is not a common usecase.

Delta exports do not support the creation of full files. Still, any of the four files might contain all products, if: 1. All products are new 2. All products have been changed 3. All products are unchanged 4. All products have been deleted

This is also reflected in the Exports A/B overview when switching to the export history tab and toggling "Show delta file changes" to on.