Difference between duplicate and reference a query in Power Query

In this video I am going to show you the difference between duplicate and reference a query in Power Query and what you can use them for.
Here you can download all the pbix files: curbal.com/donwload-center
SUBSCRIBE to learn more about Power and Excel BI!
/ @curbalen
Our PLAYLISTS:
- Join our DAX Fridays! Series: goo.gl/FtUWUX
- Power BI dashboards for beginners: goo.gl/9YzyDP
- Power BI Tips & Tricks: goo.gl/H6kUbP
- Power Bi and Google Analytics: goo.gl/ZNsY8l
☼☼☼☼☼☼☼☼☼☼
POWER BI COURSES:
Want to learn Power BI? How about you take one of our courses? Here you can find the available courses:
curbal.com/courses-overview
☼☼☼☼☼☼☼☼☼☼
ABOUT CURBAL:
Website: www.curbal.com
Contact us: www.curbal.com/contact
************
************
QUESTIONS? COMMENTS? SUGGESTIONS? You’ll find me here:
Linkedin ► goo.gl/3VW6Ky
Twitter ► @curbalen, @ruthpozuelo
Facebook ► goo.gl/bME2sB
#CURBAL #SUBSCRIBE

[@OzduSoleilDATA]

Very good lesson. Knowing the difference between referencing and duplicating queries is so handy.

[@CurbalEN]

Hi Oz!!! 👋
It is, isnt it?

[@shamf6624]

Which is efficient? If we don't look at the reasons for it. As both pull data twice from source

[@romankultajev3660]

As usually - saved my day! Thank you!

[@filipeoliveira5489]

Awesome! Thank you!

[@RipRoarLB]

Thank you for the concise explanation and demonstration!!

[@soy34mb]

As always, you open my mind for new things to do with your simple examples, Thanks!!!

[@CurbalEN]

Wonderful, glad to hear!
/Ruth

[@IlariaLongoDorni]

thank you! very useful

[@robertotm8710]

Gracias Ruth! This is very useful.
Just to make sure - if I duplicate a query, and then I delete a column from the original table, this will not affect the duplicate table. However, this would add processing time as the table needs to be loaded twice?

[@allabout1135]

My dear Ruth, I wish I would see this video some weeks ago. One of my analytical tools would be way easier. Thanks, will use in future.

[@CurbalEN]

I rebuild my models all the time, it comes with the territory 😂😂

[@ayobamiologun9184]

Very useful tip. Thank you Ruth.

[@CurbalEN]

Thanks Ayobami!
/Ruth

[@VinceM797]

Well explained, thank you!

[@CurbalEN]

Excellent!

[@sameerrazakhan4857]

good video thank you

[@Graylinepartners]

Thank you for your great content. I like your easygoing manner of presenting as well. Please keep up your great work. Question: Even if I use "Reference" instead of Duplicate, Power BI makes an additional call to the source data. Does this happen in your example as well? The Products table calls to the source and then the table referencing the Products table also calls to the source?

[@diegoj9056]

Yes, reference and duplicates call the source. Some sources allow catching the referenced query if you deactivate parallel processing

[@asutoshkumar1793]

the best explanation

[@CurbalEN]

Thanks!
/Ruth

[@denpries]

@ruth, what I am more curious about, is what the difference is in terms of data load / performance. So imagine a source table 'product' and then, for the sake of example, 5 other tables that start with a reference =producttable after which all 5 have different steps. Is this better performance wise than just duplicating the producttable 5 times and applying seperate steps?
Of course, from maintenance perspective the reference approach is better here, but that is another story

[@CurbalEN]

Great question!
In my mind as Power Query is reading from a previous Query when referencing, it should be faster than with duplicate, as it can skip all steps and load the table already pre-cleaned, but the only way to know for sure is to test that hypothesis!!
/Ruth

[@nassu82]

@@CurbalEN Yes, it will be faster but, RAM&CPU consumption will be huge with a large volume of data! It can be problematic. ;)

[@baogiapv]

Hello, thanks for the video. From performance point of view which one would you suggest?

[@CurbalEN]

Reference as your tables will load only once.
/Ruth

[@achelle0]

@@CurbalEN I believe this is incorrect. It loads twice even with reference

[@joelluis4938]

Hi!
I've found the ''reference'' option this week and I wanted to ask you something.
There is any difference between ''Duplicate'' and ''Reference'' if I just want to take the Fact Table and create some extra ''copies'' to build my dimensional tables which only pick some columns from the fact table that I could ''Duplicate or reference''..
I don't know if there is any difference in term of performance or if it's the same ?

[@achelle0]

It will be the same. Power bi still makes 2 calls even though you’re referencing. You would think it would only load the primary table from the data source but it loads twice

[@victor8068]

thx!!

[@shoaibrehman9988]

Hi Curbal
Your channel is very fruitful but there is separate section or playlist for power query videos. Please do it

[@CurbalEN]

There is one already, it is called power query:
m.ua-cam.com/play/PLDz00l_jz6zxF_OSmQhWBCVmQOaROoxWj.html
/Ruth

[@alejandrogerardofloresbard5601]

Thxs a lot!!!!

[@CurbalEN]

You welcome !!
/Ruth

[@papachoudhary5482]

Thanks! Madam

[@CurbalEN]

My pleasure 😇
/Ruth

[@stevennye5075]

well done

[@CurbalEN]

Thanks Steven!
/Ruth

[@ironpolux]

"sometimes you want, sometimes you don´t" :P. Thanks for the vid.

[@CurbalEN]

😂

[@EricaDyson]

Alles ist klar!

[@CurbalEN]

Wunderbar!
/Ruth

[@SANJIVRAI6693]

Even the Reference Table fetches the data again, so its still getting the data twice

[@CurbalEN]

Sure, but the data is getting in the reference table already cleaned (I think), so it should be faster.
/Ruth