1select @@global.shared_memory; 2@@global.shared_memory 30 4select @@session.shared_memory; 5ERROR HY000: Variable 'shared_memory' is a GLOBAL variable 6show global variables like 'shared_memory'; 7Variable_name Value 8shared_memory OFF 9show session variables like 'shared_memory'; 10Variable_name Value 11shared_memory OFF 12select * from information_schema.global_variables where variable_name='shared_memory'; 13VARIABLE_NAME VARIABLE_VALUE 14SHARED_MEMORY OFF 15select * from information_schema.session_variables where variable_name='shared_memory'; 16VARIABLE_NAME VARIABLE_VALUE 17SHARED_MEMORY OFF 18set global shared_memory=1; 19ERROR HY000: Variable 'shared_memory' is a read only variable 20set session shared_memory=1; 21ERROR HY000: Variable 'shared_memory' is a read only variable 22