Hi Micheal, Just 1 db is fine enough for me. I would choose a cloud platform because I don't want to maintain the hardware myself and install os, application server etc. Or even worse have to put up another application server and have to load balance it.
That's why I like the elasticity of the Cloud. If I would more resources, cpu etc. I will pay for it. Again 1 db is fine enough, in most web applications I have seen so far the application server and web servers are clusters but there is always just 1 db. So why not support e.g. MySQL as relational database within GAE? ;-) I agree a relational database is a very sophisticated technology. That's why so many people like it! That's also why Amazon support both SimpleDB and e.g. MySQL I guess. They had the same questions. Whatever hosting environment you choose (shared hosting or nowadays cloud, ...) a relational database is always supported (and used by many people). I don't agree with your statement "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." Cheers, Marcel On 9 apr, 19:55, michaelg <mike...@gmail.com> wrote: > 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 -~----------~----~----~----~------~----~------~--~---
