Q. How does Postgres-XL relate to Postgres-XC and Stado?
The project includes architects and developers who previously worked on both Postgres-XC and Stado, and Postgres-XL contains code from Postgres-XC.
The Postgres-XL project has its own philosophy and approach.
Postgres-XL values stability, correctness and performance over new functionality. The Postgres-XL project ultimately strives to track and merge in code from PostgreSQL.
Postgres-XL adds some significant performance improvements like MPP parallelism and replan avoidance on the data nodes that are not part of Postgres-XC. Postgres-XC currently focuses on OLTP workloads. Postgres-XL is more flexible in terms of the types of workloads it can handle including Big Data processing thanks to its parallelism. Additionally, Postgres-XL is more secure for multi-tenant environments.