Google App Engine does not seem to be using a relational database. It looks like a hashtable. Joins are not possible. In other words, yes some relational database functionality is not possible to be scalable at the prices Google offers. So Google does not provide a relational database. But this is thinking at Google scale. If you have a small operation relational database is much easier to use with the extra functionality it has compared to Google persistence. Needless to say Google is Python centric and sticking to Java might keep things flexible. Regards, Ali
--- On Sun, 10/12/08, Amir Michail <[EMAIL PROTECTED]> wrote: > From: Amir Michail <[EMAIL PROTECTED]> > Subject: Relational database scalability > To: "Derby Discussion" <[email protected]> > Date: Sunday, October 12, 2008, 11:07 AM > Hi, > > I've been using Derby db but will very likely move my > development to > the Google app engine to save money and create scalable > code. > > Unfortunately, the Google app engine does not support > schemas because > apparently they would slow things down too much. > > Is this a general problem with relational databases? They > have > problems scaling efficiently? Any insight into why? > > Also, what's wrong with checking database integrity > occasionally with > respect to a schema? Wouldn't that give you the best > of both worlds? > > Any chance that a Derby db layer could be added on top of > the Google > app engine to provide schema checking on demand? > > Amir > > -- > http://chatbotgame.com > http://numbrosia.com > http://twitter.com/amichail
