Turn this on for a workspace to capture OneLake access activity as JSON logs, kept in a lakehouse on the same capacity, showing who read or changed which data, when, and by what means.
Read more: Microsoft Learn
In the Ultra Transcenders books
Each book explains OneLake diagnostics in context, with comparison tables and the common traps.
Terms in this definition
- TURN
If a direct link can't be made, RDP Shortpath for Windows 365 relays UDP traffic via Microsoft servers on port 3478 instead.
- Workspace
Teams in Power BI and Microsoft Fabric collaborate in this folder-style container, which groups items such as reports, semantic models and lakehouses, controls who can access them and is assigned a capacity.
- OneLake
Built on Azure Data Lake Storage Gen2, it is the one logical data lake for an entire Microsoft Fabric tenant, provisioned automatically, and the place where every Fabric workload keeps its data.
- JSON
Text-based format for structured data. ARM templates and Cosmos DB documents are written in it, and most Azure REST APIs exchange request and response bodies as application/json.
- Lakehouse
Fabric storage item in OneLake that holds structured and unstructured content side by side: managed Delta tables go under Tables, other files under Files. Spark is used for processing, and a read-only SQL analytics endpoint allows T-SQL queries.
- Capacity
A reserved block of compute for a tenant whose size is fixed by its SKU; Fabric F SKUs express it in capacity units (CUs). Workspaces assigned to it unlock features like Copilot, and from F64 upwards people with free licences can view Power BI content.
- CRUD
Shorthand for create, read, update and delete, the four basic things you do with data. Data-plane roles in Azure Cosmos DB, for instance, authorise those operations on items.
Related terms
- Immutability
An optional setting for OneLake diagnostics that locks diagnostic logs as write-once, read-many for a chosen retention period, so nobody can edit or delete them. Once set, the period cannot be reduced or undone.
- Operation list
A page on Microsoft Learn that lists all Fabric audit log operations by friendly name and operation name. It points out that OneLake data-plane activity isn't fully captured by the audit log and that OneLake diagnostics fills that gap.