I'm used to the concept of working with functions and php files, where there is a need to organise things into logical files/functions... rather than a 10,000 line index.php file.

But I have a situation where it seems like I should start a new database, because even though the applications will talk to each other down the development track, they are also stand-alone entities. I know its possible to work with different databases at the same time in php, but it is a bit of a pain to do... with connection handlers, extra db users etc.

What is the general consensus? To have a very large database with dozens of tables, or to split it off.