Slow PowerBi Desktop Refresh

[scaramangamp]

Hi,

I have a PowerBI file with 10 data sources, some Web, some ODBC some local files.

The Web files are very large (40MB) however I only select a few columns. There are till 30,000 + rows.

When I Refresh All, the different queries stay on "Waiting for other queries..." or "Evaluating" They stay like this for a few hours before they (sometimes) start downloading. It will then occassionally error, however it will still take a few hours for this to happen. When the data actually starts downloading it takes aroud 20-30 minutes to download, therefore I don't why it takes a few hours during pre-downloading. I have a schedule refresh for this data set (using which works and take aroud 20-30 minutes when tirggered online).

I have tried to modify the 'Data load' options as suggested in other solutions but it doesn't make a difference.

Any help would be much appreciated. Thanks.

[MattAllington]

I'm thinking it could be a query folding issue. Reza Rad blogged on this topic this week.  Read about it here and see what you think. 

http://radacad.com/not-folding-the-black-hole-of-power-query-performance

otherwise, time to debug with a bi are search. Create a copy of the workbook and delete half the queries.  See if the problem persists. Try again with the other half. Chip away and try to find if it is just one or two of them, then go from there

[scaramangamp]

Hi all,

I am a desktop file with a few different data sources:

• Web files (mainly)
• ODBC
• Local files

 A couple of files are big at source (40MB) however using the query editor I am only taking about 15% of this.

They have around 30k+ rows or more.

The problem I am encountering is not the time to download the data (only it has downloaded the first row) but the time to start downloading, from when I pretty the 'refresh all' button it can spend up to 2 hours with the pop up just showing each dataset is "Waiting for other queries..." or "Evaluating". It sometimes then fails with a query problem, othertimes it starts to download.

When scheuling a refresh (using the gateway) if it succeeds it takes about 30mins.

I have tried playing around with the 'Data load' settings as suggested in a solution to a similar problem but to no avail. 

Would very much appreciate any assistance. Thanks.