The database landscape is changing. For decades, relational databases like MySQL and PostgreSQL have been the default choice for web applications. But in the past few years, a new category of databases has emerged that challenges many assumptions about how we store and query data. MongoDB, one of the most popular NoSQL databases, represents a fundamentally different approach to data persistence—one that aligns naturally with how web developers actually build applications.
If you're building web applications in 2012, MongoDB deserves your attention. This isn't about abandoning relational databases entirely, but about understanding when a document-oriented approach makes more sense than tables and foreign keys.
Understanding NoSQL and Document Databases
Before diving into MongoDB specifically, it's worth understanding what NoSQL actually means and why this movement has gained so much momentum.
NoSQL doesn't mean "no SQL" but rather "not only SQL." It's an umbrella term for databases that don't follow the traditional relational model. Within NoSQL, there are several categories: document stores (like MongoDB), key-value stores (like Redis), column-family stores (like Cassandra), and graph databases (like Neo4j).