But an image can be scaled in a farm of servers. A persistent Smalltalk can
have valuable objects transparently stored in a shareable support. 

I've implemented in Squeak a *proof of concept* of this idea in a system
that can store in a relational database the objects without having to map
classes to tables. It uses the same intention that the VM uses to store
objects in RAM. It uses the RDBMS as if it where an analogy of the RAM. I
based the design on the blue book. The idea is not original Sun has played
with something like this for Java.

Every instar value you change in an object is made ACIDly. Is slow because
the support is slow. Write and read barriers can help a lot. Concurrency
also should be managed.

But you can make a really big image with this by scaling it as much as
PostgreSQL can scale.

Cheers,

Sebastian Sastre


> -----Mensaje original-----
> De: squeak-dev-bounces at lists.squeakfoundation.org 
> [mailto:squeak-dev-bounces at lists.squeakfoundation.org] En 
> nombre de Marcel Weiher
> Enviado el: Miércoles, 29 de Agosto de 2007 20:51
> Para: The general-purpose Squeak developers list
> Asunto: Re: pipe
> 
> 
> On Aug 26, 2007, at 3:10 AM, Fabio Filasieno wrote:
> 
> >> Smalltalk is very different - you always can add behaviour 
> you need 
> >> to the other object and the application logic is 
> distributed across 
> >> the system.
> >
> > That's not the point, but you are right, Unix and Smalltalk are 
> > different.
> > In regard to the black boxes thing.
> 
> I think a lot of the differences are superficial, but one seems very
> deep:  Unix's unifying principle is extensional, Smalltalk 
> intensional.
> 
> That is, Unix gets its power from the fact that everything is 
> just represented as bytes, and you can pipe those around.  
> Who cares what they mean?  To the refined tastes of us 
> Smalltalkers that seems barbaric, but it is very powerful in 
> a very pragmatic sort of way, and gets you extremely loose 
> coupling and late binding (of things other than the fact that 
> it's all just bytes).  Of course, you lose moving to higher 
> levels of abstraction, and no, XML doesn't really do it.
> 
> Smalltalk, on the other hand, does really well with modelling 
> semantics, as objects sending messages, but has a hard time 
> extending its unifying principle outside the image.  Which is 
> somewhat ironic considering the idea was connecting things 
> and late, late binding.
> 
> Marcel
> 
>