Setting up a repository

[Germán Arduino]

Thanks by the response Chris.

Thinking a bit about your responses, I started migrating the business
objects to Magma, and I already completed some collections!.

But I must to learn a lot yet, and surely will be here asking again soon :)

Cheers and thanks by the help.

Germán.


2008/4/16, Chris Muller <asqueaker at gmail.com>:
>
> Hi Germán,
>
>
> > business objects and, as I don't know another way, I tried (as stated on
> > Getting Started):
> >
> >  MagmaRepositoryController
> >  create: 'c:\myMagmaFolder'
> >  root: Dictionary new
>
>
> The getting started only uses a Dictionary because it doesn't want to
> be partial to any sort of domain.  It is actually something I
> recommend against doing nowadays.
>
>
> > were instead "Dictionary new" I did "MySystem current" (the singleton
> > instance that permit to reach all the objects of the system).
>
>
> Now, you do NOT want to have your root persistent object continue to
> be a referenced in the image by some class variable.  This will cause
> the entire database to remain in memory and slow your commits to a
> crawl, among other potential identity issues if you have multiple
> users.
>
> Instead, just treat the repository root as the new "location" of your
> singleton instance, accessed by "mySession root".
>
>
> > And here start the doubts:
> >
> > 1. Soon I get the serialization problem with the 10MB limit. How I
> should
> > manage this situation to create the repository by parts, to avoid the
> size
> > problem, doing commits more frequently if all I can do is point my whole
> > system to #root: ?
>
>
> If you have a large model already in the image that you need to
> initially persist, you can simply eliminate the 10-meg safety limit
> check and commit the thing in one big transaction.  Be patient, it may
> take a while, but its a one-time thing.  Once committed, you can
> reinstate the safety check and access the model normally.
>
>
> > 2.  If the system were little (not problem with the serialization
> limit),
> > only doing the above sentence I get the repository and the objects
> > persistent?
>
>
> I may not be reading what you're asking here correctly, but I think
> the answer is yes.  You can do "one big commit" just for the initial
> "load" and then after that your application program should commit
> single "units of work", changes to the model that must be committed as
> a whole (like a monetary transfer from one account to another), but
> only that unit of work, as is reasonably feasible.
>
>
> > 3. Is acceptable to use a class that inherits from Object instead
> Dictionary
> > (as in the example) to point the root object? Considerations of each
> > alternative?
>
>
> Yes, not only is it acceptable, it is recommended to use a meaningful
> domain object as your root instead of a not-so-meaningful Dictionary.
>
>
> > 4. Is acceptable/possible to have more than 1 repository to 1 system ?
>
>
> Yes, not only is it acceptable, it is recommended to partition your
> domain by meaningful boundaries.  For example, in my system I separate
> the Accounting domain from the Contacts; each in their own repository,
> even though Accounts reference Contacts residing in the other
> repository.  This is accomplished via MagmaForwardingProxy.
>
> This partitioning provides many benefits.
>
>
> > Well, it's all for now, sorry if are so simple questions, but as I've
> said,
> > I'm stating with Magma.
>
>
> Cheers,
>
>   Chris
>
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