On Tue, 2006-08-08 at 07:35 +0800, Russell Keith-Magee wrote: [...] > > For those late to the discussion, it should be noted that this was one > of the ideas proposed for implementing inheritance. It was rejected on > two grounds: > > 1) Lack of support for legacy databases > 2) The number of joins that would be required for queries in the > general case.
More for the first reason than the second, I thought. The join numbers are as small as possible when you have a discriminator (because you can work out precisely the right tables to join); it's one of their advantages. As soon as we threw out discriminators, true transparent polymorphism (duck typing) became harder because the join numbers now became O(# of nodes in the inheritance tree). Regards, Malcolm --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-developers -~----------~----~----~----~------~----~------~--~---
