Can a single-node database be switched to a dual-node or three-node database?

Yes, a single-node database can typically be switched to a dual-node or three-node database, depending on the database system and its architecture. This process is often referred to as scaling out or adding nodes to achieve high availability, fault tolerance, or improved performance.

Explanation:

1. Single-Node Database: A database running on a single server, which handles all read/write operations. It is simple but lacks redundancy and can be a single point of failure.
2. Dual/Three-Node Database: Adding more nodes (servers) to distribute workloads, replicate data, or ensure failover capabilities. Common in clustered or distributed database systems.

How It Works:

• Replication: Data is copied across nodes (e.g., master-slave or multi-master setups).
• Sharding: Data is split across nodes to distribute load.
• Clustering: Nodes work together to provide redundancy and failover.

Example:

If you're using a MySQL single-node database, you can set up a master-slave replication (dual-node) or group replication (three-node) to enable failover and read scalability. For PostgreSQL, you can use streaming replication or Patroni for high availability.

Tencent Cloud Recommendation:

For managed database solutions, Tencent Cloud offers TencentDB for MySQL and TencentDB for PostgreSQL, which support one-click scaling from single-node to multi-node (e.g., primary-secondary or cluster modes). These services handle replication, failover, and scaling automatically, ensuring high availability and performance.