This built-in global variable contains the schema name of the currently executing routine.
If the ROUTINE_SCHEMA global variable is referenced outside a routine execution context, the value of the variable is NULL.
The value of the ROUTINE_SCHEMA global variable is set only for procedures and compiled functions: the value always reflects the schema name of the currently executing routine.
The value does not change for inline functions or methods: the value remains the same as it was when the inline function or method was invoked.