SET @orig = @@global.innodb_defragment; SELECT @orig; @orig 0 SET GLOBAL innodb_defragment = OFF; SELECT @@global.innodb_defragment; @@global.innodb_defragment 0 SET GLOBAL innodb_defragment = ON; SELECT @@global.innodb_defragment; @@global.innodb_defragment 1 SET GLOBAL innodb_defragment = 100; ERROR 42000: Variable 'innodb_defragment' can't be set to the value of '100' SELECT @@global.innodb_defragment; @@global.innodb_defragment 1 SET GLOBAL innodb_defragment = @orig;