Known issue - Data warehouse with more than 20,000 tables fails to load
A data warehouse or SQL analytics endpoint that has more than 20,000 tables fails to load in the portal. If connecting through any other client tools, you can load the tables. The issue is only observed while accessing the data warehouse through the portal.
Status: Open
Product Experience: Data Warehouse
Symptoms
Your data warehouse or SQL analytics endpoint fails to load in the portal with the error message "Batch was canceled," but the same connection strings are reachable using other client tools.
Solutions and workarounds
If you're impacted, use a client tool such as SQL Server Management Studio or Azure Data studio to query the data warehouse.