PostgreSQL reconsiders its process-based model
In the fast-moving open-source world, programs can come and go quickly; a tool that has many users today can easily be eclipsed by something better next week. Even in this environment, though, some programs endure for a long time. As an example, consider the PostgreSQL database system, which traces its history back to 1986. Making fundamental changes to a large code base with that much history is never an easy task. As fundamental changes go, moving PostgreSQL away from its process-oriented model is not a small one, but it is one that the project is considering seriously.
A PostgreSQL instance runs as a large set of cooperating processes, including one for each connected client. These processes communicate through a number of shared-memory regions using an elaborate library that enables the creation of complex data structures in a setting where not all processes have the same memory mapped at the same address. This model has served the project well for many years, but the world has changed a lot over the history of this project. As a result, PostgreSQL developers are increasingly thinking that it may be time to make a change.