Kusto/Azure Data Explorer Client Query Limits

[tessaw]

Hi all,

My team is using Kusto/Azure Data Explorer for our PowerBI dashboards. We recently ran into some query limit errors. After some investigating, we found this page of documentation:
https://docs.microsoft.com/en-us/azure/data-explorer/kusto/concepts/querylimits
Setting our truncationmaxsize to a large amount, like 90000000, in our query seems to be working for now. What we're curious about is this line in the article:

While you can increase the limit without bounds, eventually you'll reach client limits which are currently not configurable.

This implies that there is a limit coming from the PowerBI side since it is a client of our query? Is there a way we can find the truncationmaxsize and truncationmaxrecords limits from the PowerBI side?

Thanks in advance,
Tessa 

[v-lionel-msft]

Hi @tessaw ,

What is the error message?

What connection mode have you adopted? Import or Direct Query?

It may be an error caused by a limitation in Power BI.

Best regards,
Lionel Chen

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[tessaw]

Hi @v-lionel-msft , the actual error in PowerBI itself was not very descriptive, it only said that some of the rows failed to refresh/load. Only once I ran the query in Kusto/Azure Data Explorer itself did I get a descriptive error message which led me to the article I listed in the original post. Specifically, the error message was:
"The Kusto DataEngine has failed to execute a query: 'Query result set has exceeded the internal data size limit 67108864 (E_QUERY_RESULT_SET_TOO_LARGE).'"

[v-lionel-msft]

Hi @tessaw ,

Considerations and limitations 

Power BI also has restrictions on connected data.

Also you can refer to this:

Ten Techniques for Optimising Memory Usage in Microsoft Power BI 

Best practices for using Power BI to query and visualize Azure Data Explorer data 

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.