Can you name databases that implement the principles of the CAP theorem?

The CAP theorem states that a distributed system cannot simultaneously guarantee all three properties: Consistency, Availability, and Partition tolerance. Different databases make a choice in favor of two out of three.

Examples of databases with different focuses:

• CP (Consistency + Partition tolerance):

  • HBase
  • MongoDB (in some configurations)
  • Zookeeper

• AP (Availability + Partition tolerance):

  • Cassandra
  • Couchbase
  • DynamoDB

• CA (Consistency + Availability):

  • Traditional relational databases (e.g., PostgreSQL, MySQL) within a single node, but they are not resilient to network partitioning in a distributed environment.

It is important to understand that modern systems often try to balance these properties using various approaches to replication and consensus.