Incremental Refresh in Data Flow Incorrectly Pulls all Data

[Anonymous]

Hi, I have worked with several microsoft employees and we cannot figure out why my incremental refresh on my power bi dataflow is incorrectly pulling all data. 

Their dataset provides a date column, but it is in unix format. I convert this to a date/time column, but I do it in SQL so that the step is "evlauated by the data source" (called [col1]). However, when I add incremntal refresh with this new date/time column, this step is "evaluated outside the data source", so doesn't this mean that the query won't fold as it should, thus not performing an incremental refresh? 

I've attached a photo of the query steps. 

Here is step #2, which was created when I used the incremental refresh tool:

 #"time_traces_1ft_view-5F636F6C31-autogenerated_for_incremental_refresh" = Table.SelectRows(Source, each DateTime.From([_col1]) >= RangeStart and DateTime.From([_col1]) < RangeEnd),

[ppm1]

You can check for folding by right clicking on your filter step and looking for View Native Query. However, you icon indicators suggest folding is not occurring. Another quick test is to use a very narrow range (e.g., one day) for RangeStart and RangeEnd and see if it refreshes quickly.

You can add steps to first convert your RangeStart and RangeEnd values into Unix time and use that in the filter step, which should fold.

Pat