I can understand your confusion, some of the comments and examples are referring to faking an array for data that already exists in the database, which I do have to admit does sound horribly redundant (I'm sure there are times when you might want to do this, but as you mentioned, have a good think about why you are needing to do that).

And although there are times when knowing about the original way something was done does indeed help your present knowledge about why things work, there are times when it can hinder, just because things used to be done a certain way doesn't mean they have any relevance to how things are done now; indeed knowing the way things used to be done may actually be a way of blocking the creative juices from coming up with a better way.

"It Depends" is the standard answer for most things in the database world; I tend to ask "Why?" first, when why has been answered, then it depends 🙂

-- End Waffle