How are data retrieved and stored in Power BI?

As organizations grow, it’s natural that the number of reports increases and the complexity of analyses grows. General analyses begin to fall short, while day-to-day business questions trigger the need for increasingly complex calculations. The result? More spreadsheets. Multiply that by the number of departments, business lines, managed sites, employees.

Now imagine all of these spreadsheets being emailed or uploaded to a shared server space for the controlling department—often just one or two people—who have to “process” the data, compare them with past reports, accounting systems, procedures, market data, etc. They often have to explain discrepancies via email or phone with each employee. All of this under time pressure. This can easily lead to data leaks, which, given the dynamic evolution of legal regulations, can have serious consequences for the organization. If you’re wondering how to avoid this, you’re in the right place. The solution may be a Business Intelligence tool like Power BI. How does it work technically? How do we retrieve and process data in the Microsoft Power BI ecosystem? Where does the data go, how is it stored, and is it secure?

Do I need to invest in a data warehouse first?

One of Power BI’s biggest advantages is its ability to retrieve, process, and merge data from many sources simultaneously. Power BI compresses data from accounting systems, ERP, CRM, SQL databases, spreadsheets, websites, and many other sources into one place, creating a single, unified data warehouse feeding final reports.

If you’re outsourcing a Business Intelligence solution, you’re probably wondering how data is retrieved and whether it’s safe.

If your organization already has a data warehouse archiving complete business and operational data, things are much simpler. You just define the scope and provide access for further work. If it’s a local server, a Data Gateway is needed to connect without transferring the data. If you’re on the cloud (Azure, AWS, etc.), appropriate connectors are enough.

If you don’t have a data warehouse—don’t worry. You don’t need to invest in an expensive, complex IT process. You just define the data scope and grant access to the person or team implementing Power BI. From there, the data is imported into Microsoft’s secure cloud, where it can be processed.

How does Power BI connect to data sources?

Power BI connects to a wide range of data sources using three main modes:

1) DirectQuery – connects directly to the data in its original repository. Data is not stored in Power BI; it just queries the source every time.

2) LiveConnection – similar to DirectQuery, but only works with specific data models:

• SQL Server Analysis Services (SSAS) Tabular
• SSAS Multidimensional
• Power BI Service

Power BI pulls metadata (like measures, attributes, relationships) from these models and only displays the data in visualizations.
3) Import – data is loaded into Power BI and stored in two main repositories: Azure Blob Storage (for datasets) and Azure SQL (for metadata and system data).

This is the most common method, offering the full Power BI experience—including Power Query, DAX, and visualization features.

Regardless of mode, Power BI can cache data temporarily to optimize performance.

Are my data secure?

Accessing Power BI reports and dashboards is done via browser or mobile app. Login requires a Microsoft account, and multi-factor authentication (MFA) can be enabled.

All data in Power BI is encrypted by default using Microsoft-managed keys. Data in Azure SQL is encrypted via Transparent Data Encryption (TDE), while data in Azure BLOB is secured with Azure Storage Encryption. You can also bring your own encryption keys with Power BI Premium.

When using the Import mode, Power BI uses the original user’s credentials to fetch data. After import, users cannot access the source system directly.

Learn more in Microsoft’s Power BI Security White Paper.

Importantly, Power BI works in a read-only mode—your original data remains untouched. All transformations happen within the Power BI ecosystem.

Power BI data sources and refresh frequency

Power BI can retrieve data from many sources. The only real limit is your developer’s skill—so it’s wise to use professional support. Power BI can pull data from:

• Spreadsheets, PDFs, text files
• SQL databases
• Data warehouses (Azure, SharePoint, Dataverse, Power Apps, etc.)
• Accounting, ERP, and trading systems
• Project management, CRM, time-tracking tools
• Web platforms (e.g., GUS, NBP, Google Analytics, Google Search Console)

See the full list on Microsoft’s website.

Sometimes internal systems aren’t enough, and external data (e.g., macroeconomic or commodity data) is needed. With custom connectors, skilled BI developers can automate importing this data into Power BI.

Reports can retrieve data from cloud (SaaS) and on-premise systems. Flat files (like Excel) updated by different departments can also feed into reports. Power BI integrates and unifies all this into a structured dataset. Data refresh frequency is tailored to your needs—monthly, weekly, daily, or more often—depending on business requirements.

How can I share Power BI reports?

We believe in data democratization—making insights accessible to more than just the management board. Managers should be “owners” of specific KPIs and targets. But that’s impossible without the right tools and procedures.

Luckily, Power BI allows secure, efficient access management to dashboards and reports. A regional manager can see only their region’s results—or also benchmark them against other regions. It’s up to you. Well-defined access rules make it easier to identify inefficiencies, manage performance, and optimize margins.

Power BI implementation in your organization

If you’re interested in Power BI or unsure about implementing it in your company, schedule a free consultation. We’ll answer your questions and help you start your journey toward becoming a data-driven organization.

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