Distributed SQL is a category of relational databases that combines the core features of traditional SQL and NoSQL systems. It provides a single logical relational database deployed across a cluster of network servers. Distributed SQL databases automatically replicate and distribute data among those servers, often called nodes, which can handle both read and write queries.
The nodes communicate with each other and form a network called a cluster, which can span across a data center or across the world in geographically distributed locations. Just add more nodes to scale. The database orchestrates how nodes in a cluster work together to store, balance, replicate, and retrieve data. When you query your tables, the database determines the best access path to your data, whether it’s close to your client or geographically distant.
Distributed SQL databases were introduced in the mid-2010s for transactional applications. They deliver core features found in both relational (SQL) or non-relational (NoSQL) databases. The database is horizontally scalable, strongly consistent, and natively provides ACID transactional support across availability and geographic zones in the cloud or in on-premises data centers.