Databases are an integral part of any software application. Databases have played a critical role for a very long time in the history of computers and software.

Databases come in a wide variety solving different problems and scenarios, that include

• Relational Databases

  • PostgreSQL - Free & Open source
  • MySQL - Free & Open source
  • MariaDB - Free & Open source
  • SQLite - Free, Embedded & Open source
  • H2 - Free, Embedded & Open source
  • HSQLDB - Free, Embedded & Open source
  • DuckDB - Free & Open source
  • Oracle - Commercial
  • SQL Server - Commercial

• NoSQL Databases

  • MongoDB
  • CouchDB
  • Cassandra

• Key / Value Stores

  • Redis
  • Memcached
  • Project Voldemort

• Multi-model & Graph Databases

  • OrientDB
  • ArangoDB
  • Neo4J

A lot more and this list can go on. However, there is a comprehensive database of databases that are/were used so far.

Enter dbdb.io, the Database of Databases created and maintained by Carnegie Mellon Database Group. The catalog has entries of 841 databases (at the time of writing this article). It is fascinating to see the number of databases that have existed, the history about them and their technical details.

The list provided about is just a tip of the iceberg and the quite popular ones!

The site provides nice search feature. It also has leaderboards grouped under different parameters.

Visit the "database of databases" to learn more!