Skip to main content
cancel
Showing results for 
Search instead for 
Did you mean: 

The ultimate Microsoft Fabric, Power BI, Azure AI & SQL learning event! Join us in Las Vegas from March 26-28, 2024. Use code MSCUST for a $100 discount. Register Now

Reply
grggmrtn
Post Patron
Post Patron

Remove duplicates without breaking query folding?

Is there a way to remove duplicates without breaking query folding? I need the folding (for incremental refresh), but I have a ton of duplicates (I go from 3 0378 271 rows to 10 472 after removing duplicates)...

7 REPLIES 7
Toddmcdermid
New Member

Use a Group By transform instead - that will fold on SQL data sources.

OPTIONAL - If you don't want an aggregate column added to the rowset (so you want it to behave functionally exactly like a remove duplicates), then edit the M that gets generated to remove the aggregate. For example, turn this:

= Table.Group(Source, {"Grouping Column 1","Grouping Column 2"}, {{"Count", each 1, type Int64}})

into this:

= Table.Group(Source, {"Grouping Column 1","Grouping Column 2"}, {})

amitchandak
Super User
Super User

@grggmrtn , how are you deleting duplicate as of now, power Query- delete duplicate ?

Yeah, exactly.

Hi @grggmrtn ,

 

This can happen if the date ranges are set NOT up to as follows: [Date] >= RangeStart and [Date] < RangeEnd. Is your upper bound set to be equal to or less than or just less than?

Refer to this thread:

https://community.powerbi.com/t5/Desktop/Problem-with-incremental-refresh-on-power-bi-premium/td-p/7... 

 

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

Hi @V-lianl-msft thanks for the reply...

 

Your answer would make sense if I had actually set ranges, but I haven't gotten to setting the ranges yet, because query folding on my dataset breaks. The final step in my query (remove duplicates) breaks the folding.

 

So my question is, how can I remove the duplicates without breaking the folding?

@grggmrtn @amitchandak 

I could use this as well, did you ever find out how to do this? 

 

Table.Distinct() breaks the fold. How do we tell the servers to return a distinct list after all our previous steps? 

Never mind. Table.Distinct() only breaks the fold if you use it to remove duplicates from a subset of the tables columns, instead of the whole table. Using Table.Distinct() on the entire table does not break the query folding.

Helpful resources

Announcements
Fabric Community Conference

Microsoft Fabric Community Conference

Join us at our first-ever Microsoft Fabric Community Conference, March 26-28, 2024 in Las Vegas with 100+ sessions by community experts and Microsoft engineering.

February 2024 Update Carousel

Power BI Monthly Update - February 2024

Check out the February 2024 Power BI update to learn about new features.

Fabric Career Hub

Microsoft Fabric Career Hub

Explore career paths and learn resources in Fabric.

Fabric Partner Community

Microsoft Fabric Partner Community

Engage with the Fabric engineering team, hear of product updates, business opportunities, and resources in the Fabric Partner Community.