Merged Values Change Before and After Query

[dax_user]

Hi all,

This article describes almost identically what is happening in my dataset: Solved: Values in table change when expanding table column - Microsoft Fabric Community. 

It seems to happen somewhat randomly; however, my index values (surrogate keys as see in screenshots) will change after expansion. How do I fix the order of my fact table and my dimension table so that it does not re-evaluate and shift the values from my merge? I've read that Sorting or Table.Buffer helps but there's no context as to when this is supposed to happen. Does it have to occur after or before every merge? Right when I load the data in from the warehouse? At the end of the dimension table creation? I'd appreciate any context as to why this happens & what I could do to prevent this in future scenarious as well.  Thanks to the community in advance for all of the help.

Below are samples of the query of both one of my dimension tables and fact tables.

[Akash_Varuna · Accepted solution]

Hi could you try first sorting those fact and dim tables based on the key columns before trying to merge those tables

Then use Table.Buffer to freeze the data afterb sorting

Then merge them

If there are transformations to the data try doing those before the merge happens

[BA_Pete · Accepted solution]

Hi @dax_user ,

The real question is: Why is it important that your rows stay in the same order? The Vertipaq engine will only muddle them up again as soon as you apply the query to the model.

Pete

[v-menakakota]

Hi @dax_user ,

Thank you for reaching out to us on the Microsoft Fabric Community Forum.

As @Akash_Varuna mentioned,try sorting those Fact and Dim tables before trying to merge those tables

Regards,
Menaka

[v-menakakota]

Hi @dax_user ,

May I ask if you have resolved this issue? If so, please mark the helpful reply and accept it as the solution. This will be helpful for other community members who have similar problems to solve it faster.

Thank you.

[v-menakakota]

Hi @dax_user ,

I wanted to check if you had the opportunity to review the information provided. Please feel free to contact us if you have any further questions. If my response has addressed your query, please accept it as a solution and give a 'Kudos' so other members can easily find it.

Regards,
Menaka.

[v-menakakota]

Hi @dax_user ,

I hope this information is helpful. Please let me know if you have any further questions or if you'd like to discuss this further. If this answers your question, please Accept it as a solution and give it a 'Kudos' so others can find it easily.
Thank you.

[PwerQueryKees · Accepted solution]

And sort order is not define in PowerQuery, except after a sort. As was stated by Imke in the solution of the post you referred to in your post.

[BA_Pete · Accepted solution]

Hi @dax_user ,

The real question is: Why is it important that your rows stay in the same order? The Vertipaq engine will only muddle them up again as soon as you apply the query to the model.

Pete

[PwerQueryKees]

Sorry, I don't get it. What is you problem? The Merge of the employees show the correct keys as far as Ican tell. What were you expecting?

Does it have to do with the sort order? I would do this last (or not at all and leave it to PBI or Excel.

[Akash_Varuna · Accepted solution]

Hi could you try first sorting those fact and dim tables based on the key columns before trying to merge those tables

Then use Table.Buffer to freeze the data afterb sorting

Then merge them

If there are transformations to the data try doing those before the merge happens