Direct Query limitations vs Import

[DAXRichArd]

Hello,

I am new to PBI Report Server and to DirectQuery. I have used PBI for about 2 years and have always parked my data in a folder somewhere. I have queried my data (import) from my parking location. Everything worked well.

I have quickly learned that when using DirectQuery I cannot create a table. I should be able to create a table if I convert my query from DirectQuery to Import. I tried this and it resulted in some failure and corrupted my file (there's a nut loose behind my computer so I'll blame it on that) (that's an attempt at humor).

It also appears that when using PBI Report Server all DAX functions are not available. Is this correct?

In my case, I closed query editor and applied pending changes. Since I cannot create a calendar table when using DirectQuery, I created new column. I want to separate and format the month from my date column.

When I type FORMAT, the function does not appear. MONTH appears to convert month into a month number, and YEAR appears to give me a 4 digit year, but FORMAT does not appear to convert month into an abbreviated text version of the month.

Is the absence of FORMAT a limitation of the use of DirectQuery or is it a limitation of PBI Report Server?

Is there a list of functions that are not available in PBI Report Server?

Please help with coffee, some form of carbohydrates (donuts, cookies), and a DAX solution.   : )

Thx in advance for all your help.

Sincerely,

Rich Ard, Houston, Texas

[Greg_Deckler · Accepted solution]

You should be able to create a composite model these days (directquery and import) depending on what version you are using and what data source you are using for DirectQuery:

https://docs.microsoft.com/en-us/power-bi/desktop-composite-models

Look at the end to see incompatible data sets.

But, yes, Power BI does not support certain functions in DirectQuery mode. See this page:

https://docs.microsoft.com/en-us/analysis-services/tabular-models/dax-formula-compatibility-in-direc...

[DAXRichArd]

Thanks Gregg. I'll review what you sent when I have a moment.

By the way, you may not recall but months ago I asked for ideas on how to promote PBI in my organization over Tableau. You provided me some ideas. It's been a battle but I've had success institutionalizing PBI. If I can be successful with PBI Report Server I think it will spell the end for Tableau in my organization. I'm in Commercial Development and have our CCO and CFO's support. Thx as always for your help!