Fabio,

A class definition is not loaded into memory until the first instance of it is created. And then that cached instance is used as a template for every other instantiation of the class. This is one reason that property assignments made on the property sheet are only evaluated when the first instance is created are seen by every subsequent instance of the class.

So VFP won't have 100,000 class definitions in memory until you have instantiated every one of them. And yes, if you've exceeded physical memory and gone out to disk with swap file performance will be in the mud.

>running an application, the app use 100000 Classes ( not objects !!! classes ),
>but medium they are in use 1000 classes only ( for to maintain on live 5000 objects ),
>the VFP's VM maintain in memory all the 100000 classes and therefore must make I a CLEAR CLASS,
>or the VM manage this automatically ( and then a Class can to be reloaded at a not deterministic time )?
>The two things are MUCH different one, and this conditions the way to construct the classes correctly.