Grants access to lakehouse or warehouse data through Spark, OneLake APIs and the explorer pane. Querying with T-SQL is a separate permission, ReadData.
Also called Read all with Apache Spark.
Read more: Microsoft Learn
In the Ultra Transcenders books
Each book explains ReadAll in context, with comparison tables and the common traps.
Terms in this definition
- 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.
- Warehouse
Fabric item offering complete T-SQL support (DML, DDL, multi-table transactions) over Delta tables held in OneLake; lakehouse SQL analytics endpoints, by contrast, are read-only.
- 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.
- T-SQL
The dialect of SQL that Microsoft uses for Azure SQL and SQL Server. Azure Monitor logs are queried with KQL instead.
- ReadData
A Fabric item permission, comparable to db_datareader, that allows T-SQL reads of all tables and views in a warehouse or SQL analytics endpoint. With only Read, a user can connect but not query.
Related terms
- DefaultReader
Every lakehouse gets this OneLake security role, which lets anyone with ReadAll permission read all of its data. If you add stricter roles without editing it or removing people from it, those people still have full access.
- Item permissions
Rights granted on one particular Fabric item, through sharing or the Manage permissions page, that can stand alone or add to whatever workspace role a person holds. Read, ReadData, ReadAll, Write and Reshare are typical examples.
- Item sharing
Giving someone permissions on one Fabric item, Read by default with extras like ReadData, ReadAll or Build, without opening up the rest of the workspace to them.