SingleStore's Online AZ Migration allows databases to switch between single-AZ and multi-AZ deployments without downtime or application disruption. Unlike traditional databases that tie availability topology to a single primary server, SingleStore distributes data across independently managed partitions. This means changing availability configuration is simply a matter of redistributing partitions across nodes while queries, transactions, and connections continue uninterrupted. The feature works in both directions — upgrading to multi-AZ for business-critical workloads or downgrading to single-AZ to cut costs on dev/test environments. The post argues this is an architectural advantage of distributed SQL over traditional primary-replica database designs.
