At some point, you might decide to delete a user-defined data field, either because it is no longer needed or it was created in error. You can delete one field at a time.
Depending on the amount of data that is involved, deleting a data field can use a large amount of space in the SQL Server transaction log. Verify that the transaction log is large enough or is set to grow automatically as needed. Also, verify that the disk drive that contains the transaction log has enough space.
To delete a data field: