Several major players built alternatives to conventional database systems: Google created BigTable, Amazon built Dynamo and Facebook initiated Cassandra. There are many other comparable open source initiatives such as CouchDB and MongoDB. These systems are part of a trend called NoSQL because it is not centered around the SQL language. While there has always been non SQL-based database systems, th
![NoSQL or NoJoin? – Daniel Lemire's blog](https://cdn-ak-scissors.b.st-hatena.com/image/square/e59c1e66f6113e2de78f3e26be91b34636d7d5d3/height=288;version=1;width=512/https%3A%2F%2Flemire.me%2Fimg%2Fportrait2018facebook.jpg)