Eric Newcomer wrote: > ORM to me is like one of those impossible tasks, like automatically > converting data types between Java and XML. I think the latter is actually easier :-) > > I think EJB3 is a big improvement over EJB2 and JPA a big improvement > over entity beans. We are in the middle of mapping JDBC and JPA to > OSGi BTW and hopefully this will result in more pluggability for > persistence providers. > > BASE is the kind of thing I was referring to in the earlier post in > that it represents a persistence design based on a different set of > assumptions. I would not really agree however with a characterization > of BASE vs ACID, since even in the BASE style systems I'm aware of, > ACID is still used by the databases when persistence happens. The > difference seems much more about the decision and timing of > persistence to stable storage than whether BASE is used in place of > ACID. AFAIK ACID is still used - if what's meant is 2PC then that is > probably a more correct comparison, i.e. BASE vs 2PC. From what I understand BASE and ACID are different concepts. If it is BASE, it is not ACID -- it doesn't matter if something underneath uses ACID semantics. If you want ACID at the top, you have to control it all the way down. BASE is about giving up some of that control in favour of weaker assumptions. Once you did that, you lost ACID from that layer upwards.
Here is the relevant paper: http://queue.acm.org/detail.cfm?id=1394128 Peter > On Fri, Jul 17, 2009 at 4:34 AM, Peter Becker <peter.becker.de > <http://peter.becker.de>@gmail.com <http://gmail.com>> wrote: > > > Rick wrote: > > I think one of the reasons that relational databases are popular as > > compared to other solutions is that they map well to the theoretical > > tools, such as relational algebra/calculus. > > > My problem is that relational databases map to most of the theory only > in theory. E.g. SQL does not map to relational algebra, it is more a > "Based upon a true story" type of thing. I've done this rant a few > types > before (including on this forum), but one of the things I really > miss is > a true implementation of the relational algebra, which includes > having a > proper notion of domains (which could easily be mapped to OO-classes). > > For an upcoming e-commerce project I suggested trying out > couchDB (as > > promoted by the posse) and sCouchDB (the Scala version of same?).... > > and a friend with an architectural leaning asked something along the > > lines of: > > > > "but can you guarantee atomicity?" > > > > which shut me up pretty quickly. > > > I believe the ACID vs. BASE question will become more dominant in the > near future, though. I am somehow afraid that many project will > pick the > BASE option when they really need ACID. > > Disclaimer: I'm a fan of EJB 3.0 > I've used only JPA, which is really not too bad. They certainly > seem to > have learned from the experiences of other products in the area, which > is unfortunately not that common with these standards. You still > need to > like ORM to like EJB3, though :-) I just find the ORM idea to be too > much of a neither here nor there thing. > > Peter > > > > > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
