How do I know if a variable is global or a session variable?
SingleStore Engine Variables have default values set at the launch of a cluster. When defining or updating a global variable, the values will be set immediately and they will persist upon new connections to the cluster. Most variables exist within this scope. You can check global variable settings with the SHOW GLOBAL VARIABLES; command.
A session variable can only be called in the currently connected session to the cluster. After a new connection is made, the settings will be lost and reset to the default. You can check session variable settings with the SHOW SESSION VARIABLES; command.