Forum Discussion

jnickell's avatar
jnickell
Helper V
3 years ago
Solved

Power Query load from Dataflow is excruciatingly slow

I'm a lttle at my wits end with this. Occassionally PowerQuery is very very slow to load previews of data, as in I've seen this before, but recently it's gotten really bad, today is unbearable.  My c...
Need Help
  • edhans's avatar
    edhans
    3 years ago

    Try clearing the cache in Power BI Desktop.


    If that doesn't help, is this on a laptop? Go to Starbucks or someplace else and see if the internet there is better. if that works, there could be a routing issue from your location that is causing a problem, or some other corporate firewall.

    Also, you don't have to wait for the preview to finish to load. Just close Power Query and tell it to save (and apply) the data. Even if it fails the first time, hitting Refresh in Power BI desktop usually clears that up.

     

    Edit: oh, what dataflow connector are you using? Does the Source line say PowerPlatform.DataFlow or PowerBI.dataflow? Whatever it says, switch it out. I personally prefer the PowerBI.Dataflow as for raw speed it is faster, but doesn't allow folding or setting incremental refresh with it.

     




jnickell's avatar
jnickell
Helper V
3 years ago

Thanks for replying. I'll try clearing the cache today. This morning when I retried at home I was prompted for a PowerBI update, working on downloading it now.  When I was trying at work I was still seeing very low bandwidth utilizations, but I was able to get the test PowerQuery preview to load, it was still slow, but it did load.

 

Regarding your other suggestions/questions:
Yes it's laptop and it seems to be reproducible even off the local office network

 

RE: Preview. I have some tables in Power BI that give me refresh error if I don't go into PowerQuery and get all my previews to be "good", so I need to get the previews in PowerQuery working so the full refresh will actually work. 

 

I am using PowerPlatform.Dataflow connector.  I had switched all of the sources in the model to the PowerPlatform becaue I thought that's where Microsoft was heading longterm. I forget where I 'heard' that.

edhans's avatar
edhans
Community Champion
3 years ago

They are, and in fact the Power BI dataflow connector says "legacy" and at some point they will remove the ability to create new connections, but I think we are a LONG LONG way from existing ones breaking. I would set one up with the Power BI connector and see if you can see a speed difference.