SET @start_global_value = @@global.innodb_file_format;
SELECT @start_global_value;
@start_global_value
Antelope
Valid values are 'Antelope' and 'Barracuda' 
select @@global.innodb_file_format in ('Antelope', 'Barracuda');
@@global.innodb_file_format in ('Antelope', 'Barracuda')
1
select @@global.innodb_file_format;
@@global.innodb_file_format
Antelope
select @@session.innodb_file_format;
ERROR HY000: Variable 'innodb_file_format' is a GLOBAL variable
show global variables like 'innodb_file_format';
Variable_name	Value
innodb_file_format	Antelope
show session variables like 'innodb_file_format';
Variable_name	Value
innodb_file_format	Antelope
select * from information_schema.global_variables where variable_name='innodb_file_format';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_FILE_FORMAT	Antelope
select * from information_schema.session_variables where variable_name='innodb_file_format';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_FILE_FORMAT	Antelope
set global innodb_file_format='Antelope';
select @@global.innodb_file_format;
@@global.innodb_file_format
Antelope
select * from information_schema.global_variables where variable_name='innodb_file_format';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_FILE_FORMAT	Antelope
select * from information_schema.session_variables where variable_name='innodb_file_format';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_FILE_FORMAT	Antelope
set @@global.innodb_file_format='Barracuda';
select @@global.innodb_file_format;
@@global.innodb_file_format
Barracuda
select * from information_schema.global_variables where variable_name='innodb_file_format';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_FILE_FORMAT	Barracuda
select * from information_schema.session_variables where variable_name='innodb_file_format';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_FILE_FORMAT	Barracuda
set session innodb_file_format='Salmon';
ERROR HY000: Variable 'innodb_file_format' is a GLOBAL variable and should be set with SET GLOBAL
set @@session.innodb_file_format='Salmon';
ERROR HY000: Variable 'innodb_file_format' is a GLOBAL variable and should be set with SET GLOBAL
set global innodb_file_format=1.1;
ERROR 42000: Incorrect argument type to variable 'innodb_file_format'
set global innodb_file_format=1e1;
ERROR 42000: Incorrect argument type to variable 'innodb_file_format'
set global innodb_file_format='Salmon';
ERROR 42000: Variable 'innodb_file_format' can't be set to the value of 'Salmon'
SET @@global.innodb_file_format = @start_global_value;
SELECT @@global.innodb_file_format;
@@global.innodb_file_format
Antelope
