For scalability and efficiency, a database solution is probably the best. That's based on the 2 to 20 or so preferences that you mentioned; assumes a number of users, now or in the future, totalling in the 100s, 1000s, or more; and also assumes preferences are stored server-side, not client-side. I'd have different advice if those assumptions are incorrect — let us know.

G'day Ken,

You are spot on with your assumptions 😀

Yes, you are right. The database solution is going to be right for this purpose. I had come across Storable mentioned a few times recently both here and in other places and thought it might be a good solution as it keeps the preferences in Perl. But I am not keeping any of the other data within Perl that is held in a database so why shouldn't preferences?

Perhaps it was shiny penny syndrome...