SET @start_global_value = @@global.innodb_limit_optimistic_insert_debug; SELECT @start_global_value; @start_global_value 0 select @@global.innodb_limit_optimistic_insert_debug; @@global.innodb_limit_optimistic_insert_debug 0 select @@session.innodb_limit_optimistic_insert_debug; ERROR HY000: Variable 'innodb_limit_optimistic_insert_debug' is a GLOBAL variable show global variables like 'innodb_limit_optimistic_insert_debug'; Variable_name Value innodb_limit_optimistic_insert_debug 0 show session variables like 'innodb_limit_optimistic_insert_debug'; Variable_name Value innodb_limit_optimistic_insert_debug 0 select * from information_schema.global_variables where variable_name='innodb_limit_optimistic_insert_debug'; VARIABLE_NAME VARIABLE_VALUE INNODB_LIMIT_OPTIMISTIC_INSERT_DEBUG 0 select * from information_schema.session_variables where variable_name='innodb_limit_optimistic_insert_debug'; VARIABLE_NAME VARIABLE_VALUE INNODB_LIMIT_OPTIMISTIC_INSERT_DEBUG 0 set global innodb_limit_optimistic_insert_debug=1; select @@global.innodb_limit_optimistic_insert_debug; @@global.innodb_limit_optimistic_insert_debug 1 select * from information_schema.global_variables where variable_name='innodb_limit_optimistic_insert_debug'; VARIABLE_NAME VARIABLE_VALUE INNODB_LIMIT_OPTIMISTIC_INSERT_DEBUG 1 select * from information_schema.session_variables where variable_name='innodb_limit_optimistic_insert_debug'; VARIABLE_NAME VARIABLE_VALUE INNODB_LIMIT_OPTIMISTIC_INSERT_DEBUG 1 set @@global.innodb_limit_optimistic_insert_debug=0; select @@global.innodb_limit_optimistic_insert_debug; @@global.innodb_limit_optimistic_insert_debug 0 select * from information_schema.global_variables where variable_name='innodb_limit_optimistic_insert_debug'; VARIABLE_NAME VARIABLE_VALUE INNODB_LIMIT_OPTIMISTIC_INSERT_DEBUG 0 select * from information_schema.session_variables where variable_name='innodb_limit_optimistic_insert_debug'; VARIABLE_NAME VARIABLE_VALUE INNODB_LIMIT_OPTIMISTIC_INSERT_DEBUG 0 set session innodb_limit_optimistic_insert_debug='some'; ERROR HY000: Variable 'innodb_limit_optimistic_insert_debug' is a GLOBAL variable and should be set with SET GLOBAL set @@session.innodb_limit_optimistic_insert_debug='some'; ERROR HY000: Variable 'innodb_limit_optimistic_insert_debug' is a GLOBAL variable and should be set with SET GLOBAL set global innodb_limit_optimistic_insert_debug=1.1; ERROR 42000: Incorrect argument type to variable 'innodb_limit_optimistic_insert_debug' set global innodb_limit_optimistic_insert_debug='foo'; ERROR 42000: Incorrect argument type to variable 'innodb_limit_optimistic_insert_debug' set global innodb_limit_optimistic_insert_debug=-2; Warnings: Warning 1292 Truncated incorrect innodb_limit_optimistic_insert_d value: '-2' set global innodb_limit_optimistic_insert_debug=1e1; ERROR 42000: Incorrect argument type to variable 'innodb_limit_optimistic_insert_debug' SET @@global.innodb_limit_optimistic_insert_debug = @start_global_value; SELECT @@global.innodb_limit_optimistic_insert_debug; @@global.innodb_limit_optimistic_insert_debug 0