Incremental Refresh with PostgreSQL - Is query folding happening?

[chad_oge]

Hello,

In PowerBI, I am using the PostgreSQL connector to query a database view.  I would like to set up incremental refresh for this view.  Through my research, I have seen as long as you can "View Native Query" in the applied steps, query folding is happening.

After applying the RangeStart and RangeEnd date filters, I am indeed still able to "View Native Query".  But, when I run "Diagnose Step" on the applied filter, I see an operation returned saying "ReportFoldingFailure".  Does this mean that query folding is actually not occurring?  And is there any solution to solve this?

Thank you

[V-pazhen-msft]

@chad_oge 

According to the official doc, it is not recommend to use nonfoldable queries. Incremental refresh fordatasets in Power BI - Power BI | Microsoft Docs

" If you see this warning and want to verify the necessary query folding is occurring, use the Power Query Diagnostics feature or trace queries by using a tool supported by the data source, like SQLProfiler. If query folding is not occurring, verify the filter logic is included in the query being passed to the data source. If not, it's likely the query includes a transformation that prevents folding."

Reference:

Query folding guidance in Power BI Desktop - Power BI | Microsoft Docs

Query folding | Microsoft Docs

PaulZheng_ Community Support Team
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[lbendlin]

Query folding is not an absolute requirement for incremental refresh.  It is certainly preferred but incremental refresh will also work with data sources that do not support folding.