Horizontal scaling of relational databases is non-trivial and Google does not offer it. I can't say if they have something internally that could work for some people, but it is such a tricky subject that it would be hard to offer a general purpose, turnkey solution. As an example, Google donated Hibernate Shards, a layer on top of the popular Hibernate ORM that is designed to work with a horizontally scaled database. They released this two years ago and it has been sitting and rotting ever since.
However, very few applications actually need a horizontally scaled database. That is why folks like Microsoft and Sun are willing to offer relational databases as part of their cloud platforms. There is almost no chance that any customer will actually need this. And chances are that a customer that did need this would probably be well past the stage where they would want to use a cloud platform anyways... As for Amazon, MySQL running on EC2 is not a horizontally scaled database. It is a vertically scaled database (i.e. you can make the box it runs on bigger, but it is still one DB on one box, plus maybe some read slaves.) Again, this is perfect for the vast majority of applications. Amazon's SimpleDB is very similar to Google's DataStore. It is not relational, but it will scale horizontally. It has many of the same restrictions and downsides that DataStore has: http://highscalability.com/current-pros-and-cons-list-simpledb Finally, make no mistake that there is no substitute for a relational database. RDBMS is very sophisticated technology. There are decades of complex mathematics and computer science behind it. Things like joins, views, ACID transactions, and integrity constraints are easy to take for granted, but not so easy to reproduce/reinvent. Many applications can greatly benefit from these standard features of most relational databases. Weighing the simplicity and scalability of GAE DataStore vs. the benefits of a relational database is one of the most critical factors in picking a cloud platform. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appengine@googlegroups.com To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~----------~----~----~----~------~----~------~--~---
