Traditional Data Processing in Power BI
Before Direct Lake, Power BI had two main ways to process data:
- Direct Query – Queries data directly from the database in real-time. The advantage is that you always get the latest data, but the downside is slow performance because every query has to go back to the source.
- Import Mode – Data is imported into Power BI and stored in a special compressed format, making queries very fast. However, imported data must be refreshed regularly, which consumes resources and duplicates data.
What Makes Direct Lake Special?
Direct Lake combines the best of both worlds. It works like Import Mode by using a column-based data storage format, but instead of importing data into Power BI, it reads directly from Parquet files stored in OneLake. This means:
- No need to refresh data manually.
- No duplicated data, reducing storage needs.
- Performance is almost as fast as Import Mode.
Why Is This Important?
Before Direct Lake, Power BI always had to rely on Analysis Services for tabular models. Now, instead of storing models inside Power BI, they live in OneLake as Parquet files. When you run a query, Power BI fetches data directly from OneLake without importing it. This makes reports more efficient and scalable.
Key Benefits of Direct Lake
- No more data refreshes – Since Power BI reads directly from the source, scheduled imports aren’t needed.
- No data duplication – Everything stays in OneLake, reducing complexity.
- Better performance – Queries are processed quickly, just like in Import Mode.
- SQL compatibility – You can now run SQL queries directly on Power BI datasets stored in OneLake.
Requirements for Using Direct Lake
To use Direct Lake, you need Power BI Premium or a Fabric SKU equivalent. It doesn’t work with Power BI Desktop or Premium Per User (PPU).
Final Thoughts
Direct Lake is a breakthrough for Power BI users, eliminating many of the challenges with data refreshes and performance. It’s built into Fabric, making Power BI even more powerful for analytics.
