Apply Query Changes : Taking too long , like hours or so

[laggerok19]

The same thing here. I confirm the bug exist as of 28-Sep-2018.

We have <10 non live data sources each extracting just ~20 rows from Tabular models my means of DAX. Extracts themselves happens in ~1 minutes in parallel, but union them into common dataset takes 12-15 minutes, while should be few seconds.

Do you know whether bug request was raised for this?

[Rookarumba]

@laggerok19 , I'm not too sure if this is a bug but is more on how PowerQuery is refreshing the query when some changes are done on it.

As of today, I'm using a method suggested by Ken Puls (I can't remember what is the name now but i can search for it and post it here again) so the queries won't evaluate everytime.

Also, I've upgraded my RAMs to 32GB and that reduces the queries timing from hours to 15 mins Max.

If you can, I suggest you update your RAM too 🙂

[laggerok19]

@Rookarumba, this happens when you refresh data at the point of time when combined data set is refreshed. Data extracts are quick, but not union operarion. Im not even saying about data transformations.

We have 8 gb RAM to union ～120-150 rows. Completely not applicable performance for application that cost that money.

What is the way suggested? If that it to publish pbx to pbi reporting service and do scheduled refresh, its not our case. SLA mins are 10 min.

[Rookarumba]

@laggerok19 the RAM works for me 🙂

this is the other methods Table.Add Key

You can find the blog post by Chris Webb

Literally, you can see that the query didnt rerun for any of your merge functions (if you have a merge function)

https://blog.crossjoin.co.uk/2018/03/16/improving-the-performance-of-aggregation-after-a-merge-in-po...

[opereira]

I have a report that basically I load few tables from excel file and accessing Windows Insight Usage from our account (Details and Summary) and take hours (6 or more) when a single change is happening. Example change the location of excel file using a new version of values. The application can switch from MSAccess Database from Excel.... In this case is worst. Failed.

Something almost at the end using Excel fail and I have to start over.... Any help will be very appreciated.

Oscar

[Rookarumba]

@opereira, do you have a sample query which you can share?

maybe i can take a quick look and see if im able to help

[Trones]

This was happening with me, then I got a System.OutOfMemoryException... It finally opened after I opened the file in another instance of excel. The process was 4.5GB and yet the file I was trying to open is 8MB... MSFT I think your PowerQuery has some memory leaks.

[kishorekvn]

Hi,

If Power BI is taking too long time to load file, follow below steps:

1. Open the excel or any other source of data and remove all empty cells apart from your data.

2. Open Power BI --->File--->Options and Settings--->Options--->Data Load---> Uncheck autodetect new relationships after data is loaded

These two steps helped me a lot to reduce time while loading data.

@Rookarumba 

[DannyTrueman]

I am also having problems with the time taken to refresh my queries.

There are 14 queries in my report, and most of them run in a reasonable amount of time. On 4 of the queries I have used the List.RemoveLastN function, and as I go through each of these queries it is on this line of code that the query is taken so long to run.

Has anybody noticed whether it is specific functions that are causing there queries to run slowly.