Case Sensitivity?

[Anonymous]

Can someone explain to me what is going on.

This is an image of a table in Power Query Editor.

This is an image of some rows from the exact same table in Power BI Desktop.

Why have the cases changed? I know DAX isn't case sensitive, but it shouldn't be changing data like this, right?

[v-robertq-msft]

Hi, @Anonymous 

Has jdbuchanan71’s reply helped you to understand the memory engine and case sensitivity in Power BI?

If so, would you like to mark your own reply as a solution so that others can learn from it too?

What’s more, I think you can also take a look at this blog, which explains the formula engine and storage engine in DAX in detail:

https://www.sqlbi.com/articles/formula-engine-and-storage-engine-in-dax/

Thanks in advance!

Best Regards,

Community Support Team _Robert Qin

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

[jdbuchanan71 · Accepted solution]

When the data move from PowerQuery into vertipaq (the in memory engine for PowerBI) it translates the data into the dictionary.  The dictonary compresses the data so it is faster to work with for the model engine and because, as far as the vertipaq engine is concerned, 'Pasco Prod' and 'Pasco PROD' are the same, it puts the first version it finds into the dictionary.  Then, when your model goes to get the value for that column from the dictionary, the entry for those two rows get the single value from the dictionary.  It just happened to be that 'Pasco PROD' was saved to the dictionary.  It could just as easily have been 'Pasco Prod' and every where Power Query sent that string in.

• Pasco Prod
• PASCO PROD
• PaScO pRod
• pASCO pROD
• etc.

Would all come out as 'Pasco Prod' because that is what the vertipaq dictionary has.