SELECT @@global.innodb_undo_logs;
@@global.innodb_undo_logs
128
SELECT @@session.innodb_undo_logs;
ERROR HY000: Variable 'innodb_undo_logs' is a GLOBAL variable
SHOW global variables LIKE 'innodb_undo_logs';
Variable_name	Value
innodb_undo_logs	128
SHOW session variables LIKE 'innodb_undo_logs';
Variable_name	Value
innodb_undo_logs	128
SELECT * FROM information_schema.global_variables
WHERE variable_name='innodb_undo_logs';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_UNDO_LOGS	128
SELECT * FROM information_schema.session_variables
WHERE variable_name='innodb_undo_logs';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_UNDO_LOGS	128
SET global innodb_undo_logs=100;
Warnings:
Warning	138	The parameter innodb_undo_logs is deprecated and has no effect.
SELECT @@global.innodb_undo_logs;
@@global.innodb_undo_logs
128
SET session innodb_undo_logs=1;
ERROR HY000: Variable 'innodb_undo_logs' is a GLOBAL variable and should be set with SET GLOBAL
SET global innodb_undo_logs=1.1;
ERROR 42000: Incorrect argument type to variable 'innodb_undo_logs'
SET global innodb_undo_logs=1e1;
ERROR 42000: Incorrect argument type to variable 'innodb_undo_logs'
SET global innodb_undo_logs="foo";
ERROR 42000: Incorrect argument type to variable 'innodb_undo_logs'
SET global innodb_undo_logs=-7;
Warnings:
Warning	1292	Truncated incorrect innodb_undo_logs value: '-7'
Warning	138	The parameter innodb_undo_logs is deprecated and has no effect.
SELECT @@global.innodb_undo_logs;
@@global.innodb_undo_logs
128
SELECT * FROM information_schema.global_variables
WHERE variable_name='innodb_undo_logs';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_UNDO_LOGS	128