select @@global.shared_memory_base_name; @@global.shared_memory_base_name MYSQL_TMP_DIR/mysqld.1.sock select @@session.shared_memory_base_name; ERROR HY000: Variable 'shared_memory_base_name' is a GLOBAL variable show global variables like 'shared_memory_base_name'; Variable_name Value shared_memory_base_name MYSQL_TMP_DIR/mysqld.1.sock show session variables like 'shared_memory_base_name'; Variable_name Value shared_memory_base_name MYSQL_TMP_DIR/mysqld.1.sock select * from information_schema.global_variables where variable_name='shared_memory_base_name'; VARIABLE_NAME VARIABLE_VALUE SHARED_MEMORY_BASE_NAME MYSQL_TMP_DIR/mysqld.1.sock select * from information_schema.session_variables where variable_name='shared_memory_base_name'; VARIABLE_NAME VARIABLE_VALUE SHARED_MEMORY_BASE_NAME MYSQL_TMP_DIR/mysqld.1.sock set global shared_memory_base_name=1; ERROR HY000: Variable 'shared_memory_base_name' is a read only variable set session shared_memory_base_name=1; ERROR HY000: Variable 'shared_memory_base_name' is a read only variable