Peter Becker wrote: > One complaint I have heard (but never verified) is that the OODBMS never > got a good story for data evolution. Migrating your relational database > schema to a new version is not always easy, but at least there are > existing practices. Assuming that your object graph will always stay the > same is probably not a good idea. > > But I'd be happy to stand corrected. ORM can be a major pain. > > Peter > > > Christian Catchpole wrote: > >> I think there are heaps of reasons including the ones you mention. >> But I think the main thing is that dev's might like the idea of a >> clean object DB, but in practice, the data held by an organization >> does not (or should not) match the objects used by a program. And >> this data shouldn't be tied to any one app. And relational people >> will argue that most enterprise data suits a relational model more >> than an OO one. >> >> Then there is the whole investment in DB technologies, admin, tuning, >> reporting, backup, replication etc. >> >> I don't know much about OO databases so I can't say how they compare. >> nope, you don't need to be corrected. RDB schemas were always much more stable than odb schemas for the simple reason that tables tend to change less often than the shape of your objects. ODB never matured enough to develop a decent solution to object versioning/migration.
Another less obvious problem. Objects in a odb all had referential integrity done the object way. This limited the database to 2 billion objects (pre 64 bit pointers). Ok, time has solved that problem but this is went RDB took persistence from a green field to a crowded space with little room left for evolution. Critical problem at a critical time == inability to go back and change history. Regards, Kirk >> On May 15, 6:12 am, Nico <[email protected]> wrote: >> >> >>> I'd like to hear the posse discuss why technologies such >>> ashttp://www.db4o.com/ >>> has not yet taken over from the traditional Relational Databases like >>> Oralce, SQL Server, MySQL.. >>> >>> Is it because the technology is not mature enough or is it because of >>> vested interest both political and monetary in large enterprises? >>> >>> >>> >> >> > > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "The Java Posse" 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/javaposse?hl=en -~----------~----~----~----~------~----~------~--~---
