Forum Discussion
Union Formula mixes columns
just a guess, in your dax union formula, maybe try no to reference the table directly, bu use something like
union (summarize(table_current, field1,field2),summarize(table_history,field1,field2))
first using the union in the data model instead of append PowerQuery is a very clever idea !! i was think about it when i read about table partition in SSAS
for example
Powerquery 1 load to table 1 - year 2016 - does not change - load only once
PowerQuery 2 load table 2 - year 2017 - do change
then create a calculated table union (table1,table2)
as far as i can see the only reason it is not working, because maybe of a bug
for example see this
Hello together
thanks a lot for you help and the replies. Unfortunately the problem is not solved, it seems not possible to accelerate the data download by having to identical tables (one with historic) and one with current data.
The DAX Union Formula mixes up some columns - guess that`s a bug and i have no clue how to avoid that. The append query solution is also not working as it always loads both table, even with unchecking "enable load" and "include in report refresh". The only result what i get with unchecking "enabling load" is a mess as it delets all relationships and measures.
So i accept that all as a bug and hope for a solution in the near future.
BR
Florian
just a guess, in your dax union formula, maybe try no to reference the table directly, bu use something like
union (summarize(table_current, field1,field2),summarize(table_history,field1,field2))
Very good point mim!
I've included your very valuable tip into my blogpost, describing this solution a bit in detail :-)
You'll also find a downloadable file there to test this approach: http://www.thebiccountant.com/2017/01/11/incremental-load-in-powerbi-using-dax-union/
Hi
Thanks for your hint with Union + Summarize
But now i have the impression that the size of my PBIX files is doubling. Can it be?
I am doing so:
Table a 5 Mb
Table b 6 Mb
Table resulting of Union + Summarize = 11 Mb
#1 Can that be?
I am quite confused here. I thought that what happens with DAX stays in the memory only. #2 Is that the case or not??
Best regards. G.
unbelievable, it seems that works. Thanks a lot mim! - i will see it finally tomorrow with the new data refresh.
tested and it works - thanks again!
UPDATE:
Ok, problem solved. It seems that problem was not in DAX, but in AAS beause changes weren't correctly pushed to data model. After updating Data MOdel correctly, everything works fine.
Dear Advocate V,I used your solution in my data model stored in Analysis Services and it worked for some time, but now returned table is mixed again and I haven't changed anything in source tables.
Funny thing is that it works fine in Analysis Services, but table is mixed in PowerBi.
Do you have any idea what could be problem?Regards,
Tomasz
Hi Florian,
I'm awfully sorry, but you're right: The bug is still there.
I tested it & must have done sth wrong (or it doesn't work consistently, which I doubt).
Don't include in Report Refresh will be ignored once you reference that table from other queries in the query editor or (what I didn't test before) from a DAX-table-creation-operation.
Pls leave your support for the bug-solution on the bug-report here - this should really be solved: http://community.powerbi.com/t5/Desktop/Disabling-quot-Include-in-Report-Refresh-quot-works/m-p/101993/highlight/false#M46007
Thx!
