What's the big deal about key-value databases like FoundationDB and RocksDB?

from blog Notes on software development, | ↗ original
Let's assume you're familiar with basic SQL databases like PostgreSQL and MySQL, and document databases like MongoDB and Elasticsearch. You probably know Redis too. But you're hearing more and more about embedded key-value stores like RocksDB, LevelDB, PebbleDB, and so on. And you're hearing about distributed key-value databases like FoundationDB...