Constant MICROMEGAS_VIEW_DEFINITION_REFRESH_SECONDS 

pub const MICROMEGAS_VIEW_DEFINITION_REFRESH_SECONDS: &'static str;

{prefix}-less env var: how often spawn_refresh_task calls reload(), and the bound on cross-replica propagation of a definition change made on a different node (the node that executed the DDL statement reloads inline instead, see rust/public/src/servers/view_ddl.rs).