SET @start_global_value = @@global.innodb_stats_method;
SELECT @start_global_value;
@start_global_value
nulls_equal
Valid values are 'nulls_equal', 'nulls_unequal', 'nulls_ignored'
SELECT @@global.innodb_stats_method in ('nulls_equal', 'nulls_unequal', 
'nulls_ignored');
@@global.innodb_stats_method in ('nulls_equal', 'nulls_unequal', 
'nulls_ignored')
1
SELECT @@global.innodb_stats_method;
@@global.innodb_stats_method
nulls_equal
SELECT @@session.innodb_stats_method;
ERROR HY000: Variable 'innodb_stats_method' is a GLOBAL variable
SHOW global variables LIKE 'innodb_stats_method';
Variable_name	Value
innodb_stats_method	nulls_equal
SHOW session variables LIKE 'innodb_stats_method';
Variable_name	Value
innodb_stats_method	nulls_equal
SELECT * FROM information_schema.global_variables 
WHERE variable_name='innodb_stats_method';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_STATS_METHOD	nulls_equal
SELECT * FROM information_schema.session_variables 
WHERE variable_name='innodb_stats_method';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_STATS_METHOD	nulls_equal
SET global innodb_stats_method='nulls_equal';
SELECT @@global.innodb_stats_method;
@@global.innodb_stats_method
nulls_equal
SELECT * FROM information_schema.global_variables 
WHERE variable_name='innodb_stats_method';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_STATS_METHOD	nulls_equal
SELECT * FROM information_schema.session_variables 
WHERE variable_name='innodb_stats_method';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_STATS_METHOD	nulls_equal
SET @@global.innodb_stats_method='nulls_unequal';
SELECT @@global.innodb_stats_method;
@@global.innodb_stats_method
nulls_unequal
SELECT * FROM information_schema.global_variables 
WHERE variable_name='innodb_stats_method';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_STATS_METHOD	nulls_unequal
SELECT * FROM information_schema.session_variables 
WHERE variable_name='innodb_stats_method';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_STATS_METHOD	nulls_unequal
SET global innodb_stats_method=2;
SELECT @@global.innodb_stats_method;
@@global.innodb_stats_method
nulls_ignored
SELECT * FROM information_schema.global_variables 
WHERE variable_name='innodb_stats_method';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_STATS_METHOD	nulls_ignored
SELECT * FROM information_schema.session_variables 
WHERE variable_name='innodb_stats_method';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_STATS_METHOD	nulls_ignored
SET session innodb_stats_method='nulls_equal';
ERROR HY000: Variable 'innodb_stats_method' is a GLOBAL variable and should be set with SET GLOBAL
SET @@session.innodb_stats_method='nulls_ignored';
ERROR HY000: Variable 'innodb_stats_method' is a GLOBAL variable and should be set with SET GLOBAL
SET global innodb_stats_method=1.1;
ERROR 42000: Incorrect argument type to variable 'innodb_stats_method'
SET global innodb_stats_method=4;
ERROR 42000: Variable 'innodb_stats_method' can't be set to the value of '4'
SET global innodb_stats_method=-2;
ERROR 42000: Variable 'innodb_stats_method' can't be set to the value of '-2'
SET global innodb_stats_method=1e1;
ERROR 42000: Incorrect argument type to variable 'innodb_stats_method'
SET global innodb_stats_method='some';
ERROR 42000: Variable 'innodb_stats_method' can't be set to the value of 'some'
SET @@global.innodb_stats_method = @start_global_value;
SELECT @@global.innodb_stats_method;
@@global.innodb_stats_method
nulls_equal
