Warehouse DDL Support for ALTER COLUMN

[JochenAbild]

Could the DDL-support in Warehouse get closer to what we have in Synapse/SQL Server?

ALTER COLUMN would be much approciated.

[TwinkleCyril]

We are actively working on adding the ALTER TABLE ALTER COLUMN (NULLABLE) support in Warehouse. Just wanted to understand your specific requirements and use cases around it. Are you specifically looking for capability to change the data type of a column to accommodate large or precise value without table reconstruction?

[JochenAbild]

Thanks for the feedback and for planning the enhancement. To answer the question: yes

In the end it would be great to have the same ALTER COLUMN possibilities as with SQL Server on premise

[CloudVasu]

@ CharlesWebbMSFT Hi Charles Webb, We deployed a table to a Microsoft Fabric workspace and originally one of the columns was created as DATE. Later we changed that column type to DATETIME2 in our SQL project and tried to deploy through DACPAC / CI-CD. During deployment, Fabric generates an ALTER TABLE ... ALTER COLUMN statement and fails because this operation is not currently supported. At the moment, the only workaround I’ve found is to drop and recreate the table, but that’s not ideal for a production deployment process. I remember you mentioned earlier that improvements around this area were being worked on, so I wanted to ask: Has support for altering column data types via DACPAC been added yet? If not, what is the recommended best practice for CI-CD deployments when changing a column from DATE to DATETIME2 without dropping and recreating the table manually? Is there any roadmap for broader ALTER TABLE support in Fabric Warehouse? Would appreciate any guidance.