PowerBI Desktop and PowerBI Service and Database

[azaterol]

Hello everyone,

I've got a question. When I wrote inefficient code and built an inefficient database structure. This means tables are copied and pasted multiple times.
How much does that affect performance?
Question 2: How does the interaction between PowerBI Desktop and the PowerBI service work? Where is the data stored that PowerBI Desktop obtains by connecting to our database? Are these stored in the Microsoft cloud? Can you explain the structure to me? Unfortunately, the explanation in the Microsoft documentation didn't help me much...

I would be grateful if you give me helpful answers.

[v-jingzhang]

Hi @azaterol 

When tables are copied and pasted multiple times in the model, the model size will be enlarged. When you use a report in Power BI Desktop, the whole data model of the report is held in the memory of your computer. And too many complex formulas will consume more memory and CPU resources for calculation than efficient formulas. All these will make the report perform slower. 

Best Regards,
Community Support Team _ Jing

[amitchandak · Accepted solution]

@azaterol , In the import mode data is first stored in pbix, and then once you published it stores on azure cloud.

Refresh on service can add data in service, independent of the desktop

In direct query mode, Power bi do not store data, only store meta and cache results for performace