One long class or many shorter classes?

Question

In PHP, is there any performance impact on using one long class with a lot of functions in it? Or is it advisable to use many small classes and call them separately when needed?

Answer 1

For the record, the size is not the important part to consider in a class. What's key to a class are the dependencies of the classes.

For example, a class that depends in the database should be separates in a special class, such a Repository / Dao / Dal / Persistence class.