Relational Table functionality is dependent on the Table Status. A Table may be in one of four states:
When a Table is first created, the Status is set to Pending. While in Pending status, you can edit the Table properties, as well as add, edit, and delete data columns. The only Action that can be performed on a Pending table is to Activate. However, a Table cannot be activated until a Unique column has been defined to act as a Primary Key. A table in Pending status cannot be deleted, and data cannot be manipulated within the table.
An Active Table is available to Deactivate, Import Data, Export Data, or Query Data. It is also available to use in Segmentation Rules and Publishing Template message content and Marketing Automation campaigns. The Table properties cannot be changed when in Active status. In order to make changes to the Table structure, you must first Deactivate the Table.
An Inactive Table is available to edit properties, add or remove fields, Activate and Delete. An Inactive Table cannot be used for Segmentation or Publishing. A Table should be set to Inactive (Deactivated) if the data is no longer in use or the Table requires maintenance (such as the addition or removal of fields).
Deleted tables are not visible within the UI, but a history of the table remains in the database once a Table is deleted. A table can only be deleted once it has been Activated, and then Deactivated.