Postgres-XL

Postgres-XL is a PostgreSQL-based scale-out cluster that handles both OLTP write intensive workloads as well as OLAP/BI type of workloads thanks to MPP parallelism.

Postgres-XL is fully ACID and supports cluster-wide Multi-version Concurrency Control (MVCC) for global consistency and performance.

There are commercial companies such as 2ndQuadrant, who provide support and consulting around Postgres-XL. Please visit http://2ndquadrant.com/en/resources/postgres-xl/ for more details.