Duplicate VS Reference in Power Query in Power BI and Fabric Dataflows

[@officesuperhero4651]

Another great video. I learn so much from you.

[@RADACAD]

Thanks :) Glad to help

[@sheasafarnezhad4178]

Thank you so much, I have a question. I have a huge fact table getting data from the OData feed daily snapshot. - When I duplicate this table, does Power BI act like this is a new query and load the data twice? Or it understand that it is the same data and shortens the refresh time?

[@RADACAD]

Duplicate will create a new query and load it twice. if you want it to be loaded once, and then re-use it, I suggest using something like the Shortcut feature in Fabric Lakehouse.

[@moeeljawad5361]

@@RADACAD Hello imagine that i am referencing the top table several times, so my bottom layer will have several tables referenced to one. if i refresh one of the bottom layer tables, will i be query sending a query again to the datasource, or will i be sending the query to the already imported table in power bi? Thanks

[@victorbatista9415]

I have a problem that I'm creating a report with RLS and I needed to use USERELATIONSHIP functions to create two different analysis from that data, but USERELATIONSHIP is not allowed with RLS. So I'm going to create another query with the exact same data to use different relationships so I don't need to use measures with USERELATIONSHIP. In terms of performance, which is better? Reference or Duplicate?

[@RADACAD]

It depends where you use the Power Query. If you use it in Power BI Desktop, no difference in terms of performance, because they will be both read from the source. If you use Power Query in dataflow, then it would use the concept of Computed Entity when you do reference, which means the performance will be better to use reference. For your scenario; another suggestion would be to use Calculated table in Power BI, that means you will create a copy of the table that is already loaded into the memory, so it won't need to read it again from the source.

[@kitykaklyne7730]

good job ! thank's

[@RADACAD]

You are Welcome!

[@kkravch]

Thank you. If it is possible, can you show how to reference a specific step in the query, not the final one. In your example if I want to reference the first query before you filtered it. I remember someone did it, but I don't remember who and how... Thanks again.

[@mrbartuss1]

You would have to use metadata. I think it was one of the Chandeep's tricks kzbin.info/www/bejne/ZoTNqZKtnseNiZI

[@RADACAD]

For that you can right click on the step and use "EXTRACT PREVIOUS" this will create a query up until previous step, and this one as a reference to that. I might create a short video about that too :)

[@mrbartuss1]

You can also use metadata. It was one of the Chandeep's tricks in his recent video with Chandoo

[@kkravch]

@@mrbartuss1 Thank you.

[@kkravch]

@@RADACAD Thank you. If you are going to do it, can you please touch on the performance side of running "extra" parallel queries, especially with mid or large dataset. Maybe vs the converting the table to record to refer the metadata way (Chandoo's). Thanks again.