"Schema changes must be coordinated across all shards to ensure the databases stay in sync. Foreign keys and globally unique indexes can no longer be enforced b

"Schema changes must be coordinated across all shards to ensure the databases stay in sync. Foreign keys and globally unique indexes can no longer be enforced by Postgres." One of my best practices for RDBMS data after executing a few sharding projects is to mandate no use of foreign keys even for v1 of a project.