In which cases is it recommended to use key-value databases?

Key-value databases are recommended in cases where:

• Fast read and write of data by a unique key is needed.
• The data structure is simple and does not require complex relationships or queries.
• High scalability and performance are more important than complex operations.
• They are used for caching, sessions, storing settings, and user data.

For example, Redis or Memcached are often used for storing user sessions or cache, where data is quickly retrieved by key without complex queries.