We have noticed many projects and configurations may be affected by the last Snowflake update. Snowflake implemented a “NOT NULL” constraint on columns set as primary keys. See this announcement for further details.
How it appears in the Keboola connection: When the column is marked nullable in metadata, we create it nullable in the workspace. Also by default we enable "convert empty strings to null" in the UI.
Action required: You need to update all the primary keys not to be “null”. Otherwise it would result in a "null in a not nullable column" error. When the column is no longer nullable, the previous NULL values will become empty strings and will no longer be unique. Please, check the detailed comment under this post describing the scenario that can occur.
Timing: Keboola managed to postpone the rollout of the change for everyone using Keboola provided Snowflake until 31st August 2021, to allow time to take action. This is a hard deadline set by Snowflake. If you’re using your own Snowflake you need to either fix the configurations or get in touch with Snowflake support.
What can help: There is a warning on your Dashboard for projects and configurations affected by this Snowflake update. In case of any questions, please reach out to our support team.