Hello! I’m considering using Cockroach for a globally distributed application that requires fast reads and writes around the world. I also like it’s scale out and replication abilities. I do have a question though. When changing a table’s schema, are there any situations where that table becomes locked? For instance, MySQL locks the whole database when changing a schema and Postgres will lock a table when adding a default value (or changing an existing column in any way). How does Cockroach handle this?