Data Storage in Power BI Datamarts

[ashishrj]

Hi folks,

I have recently explored the capability around Power BI datamarts and have a query. 

Assume I have an Excel file containing few thousands records (assume data for May 2022) and I loaded into the datamart within Power BI. Suppose next month that same file will have new set of data ( for June 2022) and I don't want loose the old data and keep intact along with the new set of data i.e. June 2022. So, ideally the datamart should consists of current month and the previous months data for computing historical data analysis using some trends.

How can I achieve this using Power BI datamarts in the online service ? I hope this should be achievable else the purpose of datamart would defeat. Thank you

[otravers · Accepted solution]

It sounds like your June 2022 Excel file won't have data from May 2022, correct? In that case load from a folder with all your monthly Excel files (May 2022.xlsx, June 2022.xlsx etc.) to build up your data history.

In case what you want is to preserve the state of the data as it was in May 2022 then have the June 2022 version of those same rows, this is called snapshotting and is possible with regular dataflows using the underlying Azure Data Lake Storage Gen 2 folder, but on the other hand the dataflows generated in datamarts and saving to SQL don't generate snapshots.

[ashishrj]

Hey thanks @otravers that's what I though of connecting to folders just wanted to double check if I am on the right path. Don't really want to create a snapshot at this point of time.

[tackytechtom]

Hi @ashishrj ,

Is it incremental refresh you are looking for? 🙂 Then this one might help you:

Get started with datamarts (preview) - Power BI | Microsoft Docs

"To set up incremental refresh for a datamart, select the table for which you want to set up incremental refresh for in the datamart editor. In the Table tools ribbon, select the Incremental refresh icon, and a right pane appears enabling you to configure incremental refresh for the selected table."

Let me know if this helps 🙂

/Tom
https://www.tackytech.blog/
https://www.instagram.com/tackytechtom/

[ashishrj]

@tackytechtom not really looking for incremental refreshes. As there will be new set of files coming every month and wanted to preserve historic data. So, the folder option I thought and as suggested by @otravers as well should suffice