> Squeak image is not designed as a multi-user, transactional image so using
the
> image in that way can be a headache when your application grows.

I was thinking thath squeak is developed especially about this.


2006/3/17, Diego Fernandez <diegof79 at gmail.com>:
>
>
> On 3/16/06, William G. Davis <william_gordon_davis at yahoo.com> wrote:
>
> Right now I have a class that stores objects for later
> > retrieval in several collections. The persistence is
> > achieved by making the class a Singleton; it stores an
> > instance of itself in a class variable and provides
> > access to the object with a class message (#instance).
>
>
> Why not using a global to save the instance, instead of a "Singleton" with
> class variables?
> This is unnecessary in St.
> Singleton means "single-instance", but some people make a wrong use of
> this pattern to make well known instances --globals. Note that except for
> "null objects", is very difficult to known if class represents something
> unique, so singletons are usually used only for performance reasons.
>
>
> Is this a bad system? Should I be using something
> > else?
>
>
> Except for the singletons it's not bad :), you can design your system in
> that way and then add other persistence mechanisms when necessary.
>
> Will this cause too much of a headache when
> > upgrading Squeak or transferring data from one machine
> > to another?
> >
> >
> Yes :(
> Squeak image is not designed as a multi-user, transactional image so using
> the image in that way can be a headache when your application grows.
>
> Maybe you can use some OODB to solve this problem, (the most used OODB is
> GemStone, that is a St prepared for persistence: an image with multi-user
> and transaction support, is very powerful but is very expensive for a small
> project :(, take a look at: http://www.gemstone.com/ and
> http://minnow.cc.gatech.edu/squeak/1957 )
>
> There are some free OODB frameworks for Squeak:
> MinneStore: http://minnestore.sourceforge.net/index.html
> Magma: http://minnow.cc.gatech.edu/squeak/2665
>
>
>
>
>
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.squeakfoundation.org/pipermail/squeak-dev/attachments/20060317/5309ba66/attachment.htm