2.1. Get or Connect to Data

💡 First Principle: Connecting to data is a set of decisions, not a single click. Which connector reaches the source? Whose credentials does it use? Can data from this source safely mix with data from that one? Should the data be copied into Power BI or queried where it lives? Each answer affects whether refresh works, how fast reports are, and who can see what.

Why care? Most failed refreshes and slow reports trace back to choices made here. A wrong storage mode makes every visual crawl; a wrong privacy level blocks a query outright; a hard-coded file path breaks the day the file moves. The exam favors these decisions because they're where a data analyst's judgment matters most, and because getting them wrong is expensive to undo once reports are built on top.

The mental model is a supply contract. Before goods flow, you agree where they come from (connector and source), who signs for them (credentials), what may be mixed in the same shipment (privacy levels), whether you stock them in your own warehouse or order on demand (storage mode), and which terms can change without rewriting the contract (parameters).

⚠️ Common Misconception: DirectQuery is always better because the data is always current. Every visual interaction becomes a query against the source, so performance depends on that source, and some Power Query and DAX features are restricted. Microsoft's guidance is to use Import by default and choose DirectQuery or Direct Lake for specific reasons.