How the utilize all avaible DWU?

Category: azure sql data warehouse


Kasper Hansen Denmark on Fri, 31 Mar 2017 08:44:34

I have problem with scaling and using all available DWUs..

When I scale from 100 to 400 DWU - queries doesn't use more DWU, so it doesn't scale linearly as expected.

Can anyone help me with example queries and sample data that would scale linearly when more DWU are added.

Even with greatly distributed data and simple queries (single table sum/group by) I do not get it to utilize all DWU with xlarge resource group.

Hope that someone have an example query and data that can help me understand and prove that the scaling actually works.




Cat-Man-Do on Wed, 05 Apr 2017 02:13:59

What is your loading mechanism (e.g., SSIS, Polybase, etc.)?  

What type of statement are you running that you expect to use all of the DWU?

I highly recommend some of the articles around the execution plan like this one (  

DMS (Data Management Service) is one that tends to underperform and typically you want to reduce the data that moves between nodes which can be done a number of ways.

Kasper Hansen Denmark on Fri, 07 Apr 2017 12:11:53


Thank you - will read the link once more..

I load using BCP and that works great. I load into heap tables and transform it into a dimensial model where most of the tables are clustered indexes (not columns store since I do not have over 60 mio rows.)

But don't any one (or even Microsoft) have a simple test script (group/by query etc) that scale linearly? Right now I really don't trust that they can deliver what is stated in the marketing material..