Hello Microsoft Team,
I've stumbled across a stack overflow error which rears its ugly head if I try to Table.Combine two tables which are both based on Table.View. 😞
Any idea what's going on here, or suggestions on how we can prevent this? Is this a Power Query bug?
Cutting it down to the relevant code, here's a repo example which can be demoed in Power BI's Query Editor:
let
GetView = (state as record) =>
Table.View(
null,
[
GetType = () => Value.Type(GetRows()),
GetRows = () => #table({"Col1"}, {{"a"}}),
OnTake = (count as number) => @GetView(state & [Take = count])
]
)
,
Table = GetView([])
in
// * The following successfully return a table:
// Table
// Table.FirstN(Table, 1000)
// * All of the following die with: 'Expression.Error: Evaluation resulted in a stack overflow and cannot continue.'
// Table.FirstN(Table.Combine({Table, Table}), 1000)
// Table.Combine({Table.FirstN(Table, 1000), Table.FirstN(Table, 1000)})
Table.Combine({Table, Table})
The self-reference (i.e. the above combining Table with itself) doesn't appear to be the issue, as the stack overflow also occurs when two different views are involved:
let
GetViewA = (state as record) =>
Table.View(
null,
[
GetType = () => Value.Type(GetRows()),
GetRows = () => #table({"Col1"}, {{"a"}}),
OnTake = (count as number) => @GetViewA(state & [Take = count])
]
)
,
GetViewB = (state as record) =>
Table.View(
null,
[
GetType = () => Value.Type(GetRows()),
GetRows = () => #table({"Col1"}, {{"a"}}),
OnTake = (count as number) => @GetViewB(state & [Take = count])
]
)
in
Table.Combine({GetViewA([]), GetViewB([])})
Help here would be much appreciated! Thank you!
