Forum Discussion
Imported Data Table does not match Data Transformation result
- 4 years ago
It's a bit of a stab in the dark but can you try adding a List.Buffer() to the source step?
Source = List.Buffer(List.Sort(List.Distinct(Table.Column(CombinedData,"Pull Date")), Order.Ascending)),
It's a bit of a stab in the dark but can you try adding a List.Buffer() to the source step?
Source = List.Buffer(List.Sort(List.Distinct(Table.Column(CombinedData,"Pull Date")), Order.Ascending)),- uhdacarter4 years agoFrequent Visitor
Hello KNP,
That seems to have solved the problem. Now I wish the M Documentation had a more in-depth discussion of what List.Buffer does and when it is appropriate to use it.
Since you brought this useful little function to my attention, I have read some commentary on how inappropriate use of List.Buffer can adversely affect performance, but so far haven't had time to read more.Thank you, again!
- KNP4 years agoSuper User
Hi uhdacarter,
Yes, List.Buffer and Table.Buffer can be a bit of a mine field.
They can, and have for me, improved performance significantly in some cases but can certainly have the reverse effect also. I believe it is a guaranteed way to break query folding if you have a source that folds, but don't quote me on that.
If List.Buffer became a problem in your scenario, I guess you add the List.Sort function everywhere the source was mentioned although I'm not sure that would be efficient either.