SQL Insights

Concurrency in a Fabric Warehouse

According to Microsoft documentation, Fabric warehouses use Snapshot isolation. In the SQL Server world, Snapshot is a row-versioning-based transaction isolation level. However, unlike SQL Server, a warehouse operates at the table level, not the row level. 

What does this mean for a warehouse? The concurrency for updates and deletes is greatly reduced, which is only acceptable if multiple connections aren’t updating or deleting data in the same table.