Preview features - Query Diagnostics - reporting gap of 1h 10m when refreshing query

[Anonymous]

Hi,

When runnning Query Diagnostics on my database, the results are showing 1h 10m minutes of gap in diagnostics. 

Refreshing the main query in my database takes too long - about 30-50 minutes. The database is simple, the file size is only 1,54MB. The main query has only 15 columns, that are taking simple information from files (text or number). There aren't any complicated calculations. However refreshing the preview takes 30-50 minutes. 

I run the diagnostics to check what makes this query refresh so long, however the diagnostics stuck for 1h 10m. I started the diagnostics at 14:09. Till 14:10 there are 28 steps recorded. Then there is a gap between 14:10 and 15:19, and then another 18 steps. Refresh ended at 15:19.

What could be te reason there is such a long gap of 1h 10m with no records? Is there any way to find out the reason of it?

Below on the screen I highlighted the moment when gap appeared.

Thanks in advance for support. My database is getting bigger and the waiting time is prolonging its completion. 

[v-chuncz-msft]

@Anonymous 

It contains multiple queries. Just refresh the table you care about.

[Anonymous]

@v-chuncz-msft  I am refreshing only the table I want to run diagnostics on. And I still get the gap. Any ideas what is the reason for it?

[Anonymous]

Anyone able to support with query diagnostics issue?

#support

[Anonymous]

Today I run the same Query diagnostics as on Friday. 
On Friday the result was displayed after 1h 10m. Today after 3h 26m I had to kill the process with query not being refreshed.

I looked into the results but I cannot see any visible connection between them. 

Is there any explanation these - diagnostics as well as query refresh itself - take so much time ?