SET @start_global_value = @@global.debug_crc_break;
select @@global.debug_crc_break;
@@global.debug_crc_break
0
select @@session.debug_crc_break;
ERROR HY000: Variable 'debug_crc_break' is a GLOBAL variable
show global variables like 'debug_crc_break';
Variable_name	Value
debug_crc_break	0
show session variables like 'debug_crc_break';
Variable_name	Value
debug_crc_break	0
select * from information_schema.global_variables where variable_name='debug_crc_break';
VARIABLE_NAME	VARIABLE_VALUE
DEBUG_CRC_BREAK	0
select * from information_schema.session_variables where variable_name='debug_crc_break';
VARIABLE_NAME	VARIABLE_VALUE
DEBUG_CRC_BREAK	0
set global debug_crc_break=1;
select @@global.debug_crc_break;
@@global.debug_crc_break
1
set session debug_crc_break=1;
ERROR HY000: Variable 'debug_crc_break' is a GLOBAL variable and should be set with SET GLOBAL
set global debug_crc_break=1.1;
ERROR 42000: Incorrect argument type to variable 'debug_crc_break'
set global debug_crc_break=1e1;
ERROR 42000: Incorrect argument type to variable 'debug_crc_break'
set global debug_crc_break="foo";
ERROR 42000: Incorrect argument type to variable 'debug_crc_break'
set global debug_crc_break=0;
select @@global.debug_crc_break;
@@global.debug_crc_break
0
set global debug_crc_break=cast(-1 as unsigned int);
select @@global.debug_crc_break;
@@global.debug_crc_break
18446744073709551615
SET @@global.debug_crc_break = @start_global_value;