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JRyan
Frequent Visitor

Initial Report load very slow (5 minutes) after dataset refresh

Hi,

 

On our P1 Premium environment, after a large dataset is refreshed overnight, the first person to load a report sees a long wait (5-10 minutes) before any visuals/data are displayed.

 

Following this, as the dataset is now "in memory", all reports load very quickly as expected.

 

Is there any way we can speed up this initial load into memory - or even program the load via XMLA endpoints, etc?

 

Thanks

11 REPLIES 11
svemp
Regular Visitor

@JRyan @mayurwadhwani @deefens  

Was any one of you able to find a solution to this? I'm facing the exact same issue. Thanks! 

Alirezam
Helper V
Helper V

I personally found 'dataflow' significantly improved my processing time as the data transformation and refreshment is performed in Cloud. I am wondering if you have used it?

ibarrau
Super User
Super User

Hi. You can try debuging performance in Power Bi Desktop to check that everything is in order with videos like this:

https://www.youtube.com/watch?v=vbS7WuH6PO8

https://www.youtube.com/watch?v=eABg872TAJU

 

Hope those helps,


If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

Happy to help!

LaDataWeb Blog

JRyan
Frequent Visitor

Hi,

 

Thanks for the response - however it is not the report that is slow - it is the initial load of the dataset into Premium memory that is slow.  Once this has been completed the report loads fine and reacts quickly.  It is simply the first time that someone interacts with the report after a refresh.

 

We cannot debug this in Power BI Desktop as this connects to the live dataset and experiences the same issues - a 5 minute wait for the dataset to load into memory, and then the report loads quickly.

 

Does that make sense?

Because the first load is the slow one, that's the main reason for a slow report. The performance analyzer, as the video show, will be use to check the first load of the pages because the second one will be in cache (so it will be fast even if the report contains bad practises).

Please check the video. It sounds like you have heavy dax or visualizations. You can also be loading innecesary columns or having a problem in modeling.

Regards,


If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

Happy to help!

LaDataWeb Blog

JRyan
Frequent Visitor

Hi,

 

I think you're getting mixed up - the first load of a report is not the slow thing, it's the first load of ANY report connected to the shared dataset after a refresh - after the dataset has been evicted from memory.

 

For example I have a completely blank report with one field in, connected to the dataset (i.e. no DAX at all) and even that takes 5 minutes to load after the dataset has been refreshed.

 

No DAX, No Visualisations, no columns being loaded...just to get the DATASET to even load into memory.

 

thanks

Hello JRyan,

 

I'm having the same issue. When we refresh a heavy dataset it takes about 5 minutes just to load an embedded report, even if it's a simple report with just one table. Subsecuent loads works just fine, but since we refresh this every 30 minutes the issue is constant. Did you find any workaround?

We're using embedded Gen 1, would Gen 2 help to solve this issue?

Hi @JRyan ,

 

Did you use this feature?

Refresh of query caches 

 

Best regards,
Lionel Chen

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

Yes, this is already enabled with no difference in outcome.

 

the dataset has been evicted from premium memory and so the wait time is while it is getting loaded back in - is there any way we can either keep it in memory, or programmatically preload the dataset once the refresh has completed?

HI @JRyan , @ibarrau@v-lionel-msft 

I am facing same issue as @JRyan  is facing. Initial load is taking huge time to load. My report has no heavy dax and visualization.

Any help would highly be appreciated.

 

Thanks,
Mayur

Same here. My report uses DirectQuery only and has long initial load times both on Power BI Report Server and Power BI Service. So it can't be related due to Power BI Gateway issues. Opening it in Power BI Desktop is fast.

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