PostgreSQL Distributed Database
PostgreSQL is not a distributed database. It is a single-node relational database. All data is served from a single node, and tables are not sharded into smaller components or distributed across multiple nodes.
There are third-party extensions that can be used to operate PostgreSQL in a distributed environment. These extensions can provide different levels of connection pooling, load balancing, and sharding, which can be used to help distribute a PostgreSQL database across multiple servers. However, PostgreSQL is not natively designed for distributed systems, so using these extensions come with challenges, including management complexity and performance tradeoffs.
Another way to create a PostgreSQL distributed database environment is to utilize a SQL API that is compatible with the SQL dialect and is wire-protocol compatible with PostgreSQL. This allows application developers familiar with PostgreSQL to leverage their knowledge of PostgreSQL (as well as the standard PostgreSQL client drivers) to build an application powered by the SQL API.