This functionality is available in Data Academy 5.4.226 onwards.
On some occasions, you may find that you need to update your warehouse based on a delta feed.
A delta feed is source dataset that contains all of the changed items which need updating in the data warehouse; but because a delta feed will usually not contain a Date Modified field, a conventional incremental data load can not be used.
In this case, Data Academy has a special trick up its sleeve*.
First of all, create an "Incremental" data loader.
Then, in the Data Loader Table Details screen, enter "##ALL##" for the Source Date Modified Field.
The result of this is that Data Academy will pull ALL records from the source table, and use them to update the contents of the warehouse.
(As with all "Incremental" loads, you will need to identify the Primary Key(s) in the field list.)
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* Note that this does not work with Text data sources. To achieve similar functionality with Text sources, you will need to load the text items first into relational tables, and then run an "Insert/ Update" transformation in TRANSFORM-it.