Bug: FirstN broken with #shared or #section

[aarvidsson]

When using the #shared or #section constructs, FirstN rows seems to result in an stack overflow error. Range or RemoveLastN functions work fine. Test case:

let
Query1 = #shared,
#"Converted to Table" = Record.ToTable(Query1),
#"Kept First Rows" = Table.FirstN(#"Converted to Table",2),
#"Expanded Value" = Table.ExpandTableColumn(#"Kept First Rows", "Value", {"Namn", "Varde"}, {"Value.Namn", "Value.Varde"})
in
#"Expanded Value"

as soon as this is "closed & appied" to the model, it will result in a stack overflow. Changing the "Kept First Rows" step to a Table.Range or Table.RemoveLastN makes everything work fine.

[v-haibl-msft]

@aarvidsson

I can repro the same issue and I’ve reported it internally to Power BI Team: CRI 29896519

I’ll post here once I get any update about it.

Best Regards,

Herbert

[v-haibl-msft]

@aarvidsson

Below is the response from product team:

This is effectively working as designed. Scenarios using #shared are for advanced users who understand its limitations.

Best Regards,

Herbert

[aarvidsson]

I'm happy to hear that it's working as intended, but would anyone be so kind as to explain HOW that is supposed to work, then? Apparently I'm not "advanced" enough to understand the limitations...