There are lots of different types of databases, and we’re going to focus on kind of the major ones. We’ve got one type of databases that are called relational databases that often use a language called SQL to manipulate them, and so we’ll refer to these as relational databases or SQL databases. Some examples of relational databases are postgreSQL, which we use that in Reddit. We currently use that in Hipmunk, and lots of people use this. It happens to be my favorite. There’s MySQL, which is extremely popular, and this is used by Facebook and basically everybody. Not strictly everybody, but MySQL is far and away the most popular database, and I’m sure you will encounter it in your web development adventures. Also pretty common is SQLite, which you’ll actually use in this class. This is a really lightweight, simple database. It’s not for working on huge amounts of data, like postgreSQL and MySQL might be. It’s generally better as a replacement for where you would normally use flat files but really handy, and of course, there’s also Oracle, which is a huge company that sells the Oracle database product. And incidentally, Oracle bought MySQL a number of years ago but has largely left it free and open. These are all free. And these databases all basically work with tables. They use a language called SQL to manipulate those tables, and we’re going to talk about that in this class a fair amount, and in our general purpose, handy things. There are other databases in the world. Some examples might be Google App Engine’s Datastore, which is what we’re going to be using a lot in this class, and it’s got a lot of similarities with these relational databases, but also a lot of differences, and we’ll spend a fair amount of time talking about these differences. Dynamo, which is by Amazon, and the reason I mention this is because there is a great paper online that describes how this database works, and I’ll include it in the course notes. It’s worth a read. It’s a really nice approach, and they take a completely different approach from these SQL databases, and there’s a lot to learn there. There’s the NoSQL databases. Of these, maybe Mongo is pretty popular. Couch is pretty popular. We’re not going to discuss these much in this class, but these are products that try to solve some of the limitations that SQL places on you that we’ll get to in a moment. But in this class, we’re going to focus on kind of the basics of SQL and then Google App Engine’s Datastore and how to use those to build your web apps. Okay, quick quiz. Which database is the best?