Deleting a column vs setting it's value to empty

[Drew Kutcharian]

Hi Everyone,

Let's say I have the following object which I would like to save in Cassandra:

class User {
  UUID id; //row key
  String name; //columnKey: "name", columnValue: the name of the user
  String description; //columnKey: "description", columnValue: the description 
of the user
}

Description can be nullable. What's the best approach when a user updates her 
description and sets it to null? Should I delete the description column or set 
it to an empty string?

In addition, if I go with the delete column strategy, since I don't know what 
was the previous value of description (the column could not even exist), what 
would happen when I delete a non existent column?

Thanks,

Drew