Removes an indicated global variable, so that it no longer exists, and releases the memory associated with the global variable. Globals always allocate 255 bytes of storage. To ensure that performance is not impacted more than necessary, always erase any global variable when it is no longer needed.
PROCEDURE ERASE
(global_variable_name VARCHAR2);
Built-in Type unrestricted procedure
Enter Query Mode yes
ERASE('global.var');