Direct Lake
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Category: Integration & Analytics
Summary: Power BI mode reading Delta tables directly from OneLake — near-Import speed, always fresh.
Overview
Direct Lake is a Power BI/Microsoft Fabric storage mode that loads Delta-format data directly from OneLake into memory for reporting, without requiring a traditional Import (full data copy) or DirectQuery (live query passthrough) step. This gives near-Import query performance while always reflecting the latest data in OneLake — including data mirrored from Azure Cosmos DB — without duplicating storage or building separate ETL/refresh pipelines.
More Info & Links
DP-420 Style Practice Questions
Q1. What problem does Direct Lake mode solve compared to traditional Import and DirectQuery modes?
- A. It provides near-Import performance while reading Delta data directly from OneLake without a full data copy
- B. It replaces the need for a partition key in Azure Cosmos DB
- C. It removes the need for Delta format entirely
- D. It requires a separate ETL pipeline for every refresh
Q2. What must the underlying data be stored as in OneLake for Direct Lake mode to read it directly?
- A. Delta format tables
- B. Raw JSON documents
- C. XML files
- D. Cosmos DB backup snapshots
Answer Key
Answers are listed at the very end so you can attempt the questions first.
- Q1 (Direct Lake): A. It provides near-Import performance while reading Delta data directly from OneLake without a full data copy — Direct Lake reads Delta tables directly from OneLake, combining Import-like speed with DirectQuery-like freshness and no data duplication.
- Q2 (Direct Lake): A. Delta format tables — Direct Lake requires the data to be stored in OneLake as Delta format tables, such as those produced by Cosmos DB Mirroring for Fabric.
DP-420: Designing and Implementing Cloud-Native Applications Using Microsoft Azure Cosmos DB — term detail page
