How did you choose the type of database (PostgreSQL, ClickHouse, Redis)?

The choice of database type depends on data requirements and load:

• PostgreSQL — a versatile relational database management system suitable for complex transactions, strict data integrity, complex queries, and analytics.
• ClickHouse — a columnar database optimized for analytical queries on large volumes of data with high read speed.
• Redis — an in-memory key-value store, ideal for caching, fast data operations, queues, and sessions.

When choosing, consider:

• Data type and structure (relational or not)
• Volume and read/write speed
• Requirements for consistency and transactions
• Presence of analytical queries
• Scalability and fault tolerance

For example, if you need an OLTP system with transactions — PostgreSQL. For real-time analytics — ClickHouse. For caching and fast operations — Redis.