The article mentions Greenplum, but it's worth noting that when the code was closed, several of the original developers created an open-source fork, Cloudberry, which seems to be thriving. Cloudberry was accepted into the Apache project this year, and has synced with Postgres 14, whereas the closed-source Greenplum is still stuck on Postgres 12.
The architecture is quite ancient at this point, but I'm not sure it's completely outdated. It's single-master shared-nothing, with shards distributed among replicas, similar to Citus. But the GPORCA query planner is probably the most advanced distributed query planner in the open source world at this point. From what I know, Greenplum/Cloudberry can be significantly faster than Citus thanks to the planner being smarter about splitting the work across shards.
The architecture is quite ancient at this point, but I'm not sure it's completely outdated. It's single-master shared-nothing, with shards distributed among replicas, similar to Citus. But the GPORCA query planner is probably the most advanced distributed query planner in the open source world at this point. From what I know, Greenplum/Cloudberry can be significantly faster than Citus thanks to the planner being smarter about splitting the work across shards.