Fabric Warehouse Limitations - T-SQL

[southgrad10]

Hello,

I have created a warehouse in Fabric and was surprised to see that I could not drop a column. I understand that there are many limitations per the attached link, but I'm wondering, should we expect to be able to use ALTER TABLE DROP COLUMN in the future?  Is it doable?  Thank you!

https://learn.microsoft.com/en-us/fabric/data-warehouse/tsql-surface-area

[v-nikhilan-msft]

Hi @southgrad10 
Thanks for using Fabric Community.

You're right, currently, Microsoft Fabric doesn't directly support theALTER TABLE DROP COLUMNcommand for data warehouses, as mentioned in the link you shared. There's no official confirmation from our team regarding the availability of this feature.

Here's why:

• Focus on data immutability: Fabric warehouses prioritize data immutability, meaning data shouldn't be modified after it's loaded. Dropping columns would alter existing data, potentially breaking downstream processes relying on the original schema.
• Alternative approaches: Microsoft recommends alternative approaches for modifying tables, such as:
  • Creating a new table: Define the new table structure without the unwanted column and copy data from the original table. Then, drop the old table.
  • You can also use Lakehouse to do all the transformations and then use a copy data in pipelines to send the data to Warehouse.
  • You can also use this work around. https://www.purplefrogsystems.com/2023/10/fabric-data-warehouse-alter-table-workaround/

Hope this helps. Please let me know if you have any further queries.

[southgrad10]

Thank you for the quick and prompt response, as always.

The link that I provided is dated 11/15/2023.  Are the commands listed still the same?  I am just wondering if there is a more up-to-date source for these limitations somewhere else.

[v-nikhilan-msft · Accepted solution]

Hi @southgrad10 
Though the document was created before, we continiously update if there are any changes. Hence the document is upto date. The commands are the same.

Hope this helps. Please let me know if you have any further questions.

[v-nikhilan-msft]

Hi @southgrad10 
Glad that your query got resolved. Please continue using Fabric Community for any help regarding your queries.

[southgrad10]

Thank you!  I always enjoy getting responses from you.  Very helpful!

[v-nikhilan-msft]

Hi @southgrad10 
You're very welcome. I'm glad I could be of assistance. Its my pleasure that I could help you.
Hope you have a great day!