Best practice data import and model

[Anonymous]

Hi there Power BI Community

I have a strong technical background but I am new to Power BI Desktop. I have the following constellation:

- Monthly exactly 1 file must be imported to Power BI. I can deliver it in Excel or CSV. Typically the file has about 180'000 rows and 10 columns.

- The report and the corresponding visuals in Power BI have to be updated with the data from the previous point.

- There is no limit for an end of the report.

- The report is only used by me.

- The monthly file has the same structure like the previous file

Now I don't want an unwanted surprise in X months/years where the report would be unuseful due to the data size. Therefore I wanted to ask what you experts think would be potential risks for this report in the future, what can I do to prevent such a surprise?

I tested a table where I simulated a "mastertable" where I appended almost 40 single month files to the mastertable which resulted in about 7 million rows - had no error message. But the report has no visuals so far so I can't say if this would be a problem.

Is is correct to append the monthly table to the mastertable? I read that the folder option would be better in this case - why?

Thank you for your responses, any help is appreciated.

[ToddChitt]

• The Folder source is extrememly useful, but can be slow. If you are refreshing once a month, I suggest you live with it. 
• I have a model with 45 million rows. It is about 600 MB in size. It takes an hour to refresh, coming from Azure SQL.
• Data is compressed about 10 to 1. If you have 100 MB of data in CSV files, you will end up with a Power BI model significantly smaller, maybe 10 MB.

[Anonymous]

Thank you!

[amitchandak · Accepted solution]

@Anonymous , The first two things are Star Schema and Date table.

Prefer Single directional 1 to Many Joins. Avoid Many to Many and bi-directional join

https://www.sqlbi.com/articles/the-importance-of-star-schemas-in-power-bi/

https://www.sqlbi.com/blog/marco/2017/10/02/why-data-modeling-is-important-in-powerbi/

Date Table

To get the best of the time intelligence function. Make sure you have a date calendar and it has been marked as the date in model view. Also, join it with the date column of your fact/s. Refer :radacad sqlbi My Video Series Appreciate your Kudos.

Performace :

https://www.thebiccountant.com/speedperformance-aspects/

https://community.powerbi.com/t5/MBAS-Gallery/Microsoft-Power-BI-The-Do-s-and-Don-ts-of-Power-BI-Relationships/td-p/712566

[Anonymous]

Thank you for your explanation.