So, how do you deal with schema changes in a distributed SQL database?

We're using a distributed SQL database, think CockroachDB or YugabyteDB, for our main services and managing schema changes across all the nodes is getting pretty tough. Doing rolling updates is complicated, and we really want to avoid any downtime. Have you guys found any good ways or tips for handling schema updates in these kinds of setups? We're trying to prevent problems with availability or data that's all messed up. Would love to hear what worked for you.