Fabric Warehouse

In the Ultra Transcenders books

DP-900

Each book explains Fabric Warehouse in context, with comparison tables and the common traps.

Terms in this definition

• Data warehouse

  Built for analysis instead of transaction processing, this relational store usually links facts to dimensions using a snowflake or star layout. Microsoft's present offering is Fabric Warehouse.

• T-SQL

  The dialect of SQL that Microsoft uses for Azure SQL and SQL Server. Azure Monitor logs are queried with KQL instead.

Related terms

• Cold start

  The extra time a Fabric warehouse query can take on its first run, because data has to be pulled from OneLake into the cache, statistics built or nodes woken up. In query insights, a data_scanned_remote_storage_mb value above zero is the tell-tale sign.

• Datamart

  A Power BI item that never left preview and has now been withdrawn. From 1 June 2025, asking for a new one gave you a Fabric warehouse; from 1 November 2025 any left over stopped working altogether, so their contents had to be moved into a warehouse.

• Direct copy

  Loading a Fabric warehouse by having the Copy activity call the COPY statement straight against Parquet or delimited text files held in Azure Blob Storage or ADLS Gen2, with no intermediate step. If the format or settings aren't supported, staged copy has to be used instead.

• DQL

  Data query language: SELECT and the other read-only parts of SQL. A Fabric warehouse handles DDL and DML alongside it, while an SQL analytics endpoint is limited to querying.

• Explicit transaction

  A set of T-SQL statements wrapped between BEGIN TRAN and either COMMIT or ROLLBACK, so that edits across multiple tables either all appear at once or are all discarded. In Fabric Warehouse these use snapshot isolation, and savepoints as well as named, marked and distributed transactions are unsupported.

• Fabric Data Warehouse MCP server

  A preview MCP server hosted by Microsoft that offers one tool, executeSQL, for running approved T-SQL on a Fabric warehouse or SQL analytics endpoint. Queries run with the Fabric permissions of whoever is signed in.

• GREATEST

  Pass up to 254 expressions to this T-SQL function and it hands back whichever is biggest. Both Fabric Warehouse and SQL analytics endpoints support it.

• Inline table-valued function

  A single SELECT statement packaged as a T-SQL function that returns rows. Fabric Warehouse and SQL analytics endpoints use one as the filter predicate when CREATE SECURITY POLICY sets up row-level security on a table.