Apparently, Digg performed a big migration from MySQL to Cassandra and a big migration to their new Digg v4 architecture and now their VP of Engineering has been shown the door:

Ever since Digg launched its new site design, it’s been plagued with all kinds of trouble, not least of which is that it keeps going down. The problems with the new architecture are so bad that VP of Engineering John Quinn is now gone, we’ve confirmed with sources close to Digg.

In a Diggnation video today, CEO Kevin Rose explained some of the technical issues the site is dealing with and why it can’t simply roll back to the previous architecture. The new version of Digg, v4, is based on a distributed database called Cassandra, which replaced the MySQL database the site ran on before. Cassandra is very advanced—it is supposed to be faster and scale …

Persistence Smoothie: Blending NoSQL and SQL – see user feedback and comments at http://joind.in/talk/view/1332.

Michael Bleigh from Intridea, high-end Ruby and Ruby on Rails consultants, build apps from start to finish, making it scalable. He’s written a lot of stuff, available at http://github.com/intridea. @mbleigh on twitter

NoSQL is a new way to think about persistence. Most NoSQL systems are not ACID compliant (Atomicity, Consistency, Isolation, Durability).

Generally, most NoSQL systems have:

• Denormalization
  
• Eventual Consistency
  
• Schema-Free
  
• Horizontal Scale
  

NoSQL tries to scale (more) simply, it is starting to go mainstream – NY …

The No-SQL tag really lumps together a lot of concepts that are in fact as distinct from eachother as they are from SQL/RDBMS.

An object store is not at all similar to Cassandra and Hypertable, which is not at all like an column store. And when looking at BigTable derivatives, it’s quite important to realise that Google actually does joins in middle layers or apps, so while BigTable does not have joins, the apps essentially do use them – I’ve heard it professed that denormalising everything might be a fab idea, but I don’t quite believe in that for all cases, just like I don’t believe in ditching the structured form of RDBMS being the solution.

SQL/RDBMS has had a few decades of dominance now, and has thus become the great “general purpose” tool. With the ascent of all the other tools, it’s definitely worthwhile to look at them, but also realise that each (inluding SQL based ones) have their place. Moving all your …

It seems almost churlish to wonder whether Google could be even more successful than it already is with a different strategy, but the company’s approach to open source and open development has come into focus in recent weeks.

On last week’s podcast we discussed whether the company should see the AGPL as more of an opportunity than a threat following Jay’s post about the company releasing more code under open source licenses.

Nik Cubrilovic over at TechCrunch, meanwhile, has written an interesting …

Over the years, the database world has been buzzing with the strategic threat posed to the established players by upstart open-source database systems. Oracle and IBM would no longer be able to gouge defenseless small and medium-sized businesses of non-trivial portions of their IT budgets for a mere database licence. Oracle, IBM and Microsoft, for their part, have tried their best to respond to this threat, but it is clear that they cannot simply squash open-source products, but rather evolve with the changing landscape.

the countered threat from Oracle

Oracle made some strategic purchases in the past few years to establish a foothold in the embedded and front-end database market by acquiring Sleepycat (maintainers of BerkeleyDB) and InnoBase (makers of InnoDB storage engine for MySQL). These two also happened to provide the only two transactional backends for MySQL, whlie InnoDB is the only one to be used widely in practice. …

Todd Hoff, who apparently learned a hell of a lot during a short stint at Yahoo followed by some startups has an extremely well-written and edutaining article about how scaling to a million or more users requires jettisoning more or less everything we know and love about relational modeling.

Even though he uses bigtable (Google’s distributed hash storage system) as his example, in reality this approach works well with relational datastores like MySQL and Oracle too, you just have to think about your data differently and use the databases differently. So I’m including this article in the MySQL and Oracle categories because I think it would be of interest.

Here’s a taste of …