[hibernate-dev] Multi-Tenancy and "shared" data

Multi-tenant setups sometimes have data that is shared between the tenants (codec tables, etc). I think the first question is do we want to support this mixing? I think it is common enough that it is worthwhile to support it. And I do not think it is complicated enough to be painful to implement. As long as we assume that there is some form of database-level availability between shared, non-shared data (even for the DATABASE and SCHEMA strategies) I think we will be fine. Assuming we do support it, there is a decision we need to make about how we differentiate shared (tenant aware) and non-shared (non-tenant aware) data, especially important when we talk about the DISCRIMINATOR approach which touches on a more general outstanding decision with regard to supporting DISCRIMINATOR multi-tenancy. Basically whether entities are inclusively considered multi-tenant when the user has specified DISCRIMINATOR, or whether we expect some form of annotation stating the entity is multi-tenant. Personally, I think the inclusive approach (all entities are assumed multi-tenant) is probably the better approach. In which case we need an annotation to say "this entity is not multi-tenant". -- steve(a)hibernate.org http://hibernate.org