[ZODB-Dev] Re: AdaptableStorage and OR mapping strategy (was: AdaptableStorage and ZClass instances)

[Shane Hathaway]

Chris Withers wrote:
> Yeah, this is getting closer to a true relational mapper.
> What you really want is a mapper that behaves like this for properties 
> the most objects of a type* have and a 'bucket' mapper that shoves any 
> little extras people have added to specific objects somewhere else.
> Now, deciding what attributes go in the type-specific table and what 
> goes in the 'bucket' is very domain specific. That's something I'd like 
> to twiddle through the web, or at worst in dbtab.conf.
> 
> Is that possible?

Currently, the "little extras" get pickled and put into a bucket 
automatically.  Is that what you mean?

> * type currently means metatype for AS, right? What about CMF content 
> objects? I have plenty of these which are of the same metatype but which 
> have property sets defined by their CMF content type. Can AS support 
> descrimination based on this? It should, and if it doesn't now, I'd like 
> to help it do so in the future :-)

To be specific, meta_type is meaningful for exactly one class in AS: 
MetaTypeClassifier.  I chose this slightly complex method of 
classification to verify that AS can choose object types and 
serialization formats based on pretty much arbitrary criteria.  So yes, 
you can get AS to classify things based on other criteria, and the way 
is to use something other than MetaTypeClassifier.

Shane

P.S. I'll answer your recent long emails regarding AS soon. :-)