PolarDB - Share-nothing, Distributed database based on PostgreSQL

PolarDB for PostgreSQL (PolarDB for short) is an open-source database system based on PostgreSQL. It extends PostgreSQL to become a share-nothing distributed database, which supports global data consistency and ACID across database nodes, distributed SQL processing, and data redundancy and high availability through Paxos based replication. PolarDB is designed to add values and new features to PostgreSQL in dimensions of high performance, scalability, high availability, and elasticity. At the same time, PolarDB remains SQL compatibility to standalone PostgreSQL with the best effort.

PolarDB will evolve and offer its functions and features in two major parts: an extension and a patch to PostgreSQL. The extension part includes components implemented outside the PostgreSQL kernel, such as distributed transaction management, global or distributed time service, distributed SQL processing, additional metadata, internal functions, and tools to manage database clusters and conduct fault tolerance or recovery. Having most of its functions in a PostgreSQL extension, PolarDB targets easy upgrading, easy migration, and fast adoption. The patch part includes the changes necessary to the kernel, such as distributed MVCC for different isolation levels. We expect functions and codes in the patch part is limited. As a result, PolarDB can be easily upgraded with newer PostgreSQL versions and maintained full compatibility with PostgreSQL.