Premium vs Pro Workspace Dataflow Oddity - Query sent twice in Premium, once in Pro

[datawizardry]

I've noticed some odd behavior that's unrelated to the known query folding issue I think.

When I create a dataflow running NativeQuery on Snowflake, the query hits Snowflake one time in a Pro Workspace but twice in a Premium workspace on each scheduled occurrence. M-Code is identical in both cases (I used import json to move the queries). No incremental refresh is enabled. 

Here is sample M Code (basically this is the default Snowflake query but with folding disabled):

let

  Source = Value.NativeQuery(Snowflake.Databases("sf_url","wh_name"){[Name="db_name"]}[Data],

"<query here>

"

, null, [EnableFolding=false])

in

  Source

1) Any ideas on what is causing this behavior? (Bug or feature? Inclusive "or", surely.)

2) Any idea on a workaround? 

[lbendlin]

1. by design

2. none

Chris Webb's BI Blog: Why Is Power BI Running My SQL Query Twice? (crossjoin.co.uk)

[datawizardry]

Hello,

I believe Chris' blog is related to query folding (let me know if you think I'm missing something here): 

Power BI wants to know the schema of the table before the query actually runs, so it asks Power Query to return the top 0 rows. 

OK, I tested setting EnableFolding=true.

When I have query folding enabled, both premium and pro workspace send two queries: 

1. Select 0 rows from (<query>)
2. <query>

When I have query folding set to false, they behave differently: 

1. Pro only sends the full query once.
2. Premium sends the full query twice.
3. Neither sends the Select 0 rows. 

So there is still a difference in behavior but that would suggest setting to true as a possible workaround as sending a 0 row query is less problematic then sending full query twice. 

[lbendlin]

Good investigation.  This may warrant a ticket. Since you have a Pro license you can consider raising a Pro ticket at https://admin.powerplatform.microsoft.com/newsupportticket/powerbi