Query folding not working without message errors

[AGo]

Hello,

I'm trying to use query folding in order to activate incremental refresh.

This is my query:

let
Source = Value.NativeQuery(PostgreSQL.Database("server", "db", [CreateNavigationProperties=false]), "select * from table1#(lf)union select * from table2", null, [EnableFolding=true]),
#"Filtrate righe" = Table.SelectRows(Source, each [timestamp] <> null and [timestamp] <> ""),
INCREMENTAL = Table.SelectRows(#"Filtrate righe", each [timestamp] >= RangeStart and [timestamp] < RangeEnd),..........

RangeStart and RangeEnd are parameters requested to activate incremental refresh.

If I click on Show Native Query on the INCREMENTAL step (which is the last step with this option) it returns correct sql with WHERE statement.

If I look on my postgres db at the query received by DBMS that is running, it is not the folded query but the first one declared in the Source step of mquery.

How can I solve this?

Thanks

[mwegener]

Hi @AGo.

Patrick tells in this video that there is no query folding at Native Query.

https://www.youtube.com/watch?v=DWbh7xp08l0

[AGo]

Are you sure? Whene he's speaking about query folding non-functioning the function he's using doesn't contains a Value.NativeQuery function. I instead succeed in viewing the native query result on my third step, the problem is that PowerBI doesn't send it to the DBMS correctly.

Maybe @ImkeF can help.

Thanks

[ImkeF]

Hi @AGo 

To my knowledge, Query folding will stop after you've used individual SQL code.

In your case, in the Source-step.

So your result doesn't surprise me.

But what I find surprising though, is that the native queries are shown in the subsequent steps.

How sending that query in the first step (Source) instead?

Edit: Check this post how to include query parameters into native SQL-calls: https://community.powerbi.com/t5/Desktop/Parameterized-SQL-Query-with-query-folding/td-p/171503 

[mwegener]

Hi @AGo ,

are you sure that you see the query of the last step and not the query of the preview cache?