1SET @start_global_value = @@global.innodb_background_scrub_data_uncompressed; 2# 3# exists as global only 4# 5select @@global.innodb_background_scrub_data_uncompressed; 6@@global.innodb_background_scrub_data_uncompressed 70 8select @@session.innodb_background_scrub_data_uncompressed; 9ERROR HY000: Variable 'innodb_background_scrub_data_uncompressed' is a GLOBAL variable 10show global variables like 'innodb_background_scrub_data_uncompressed'; 11Variable_name Value 12innodb_background_scrub_data_uncompressed OFF 13show session variables like 'innodb_background_scrub_data_uncompressed'; 14Variable_name Value 15innodb_background_scrub_data_uncompressed OFF 16select * from information_schema.global_variables 17where variable_name='innodb_background_scrub_data_uncompressed'; 18VARIABLE_NAME VARIABLE_VALUE 19INNODB_BACKGROUND_SCRUB_DATA_UNCOMPRESSED OFF 20select * from information_schema.session_variables 21where variable_name='innodb_background_scrub_data_uncompressed'; 22VARIABLE_NAME VARIABLE_VALUE 23INNODB_BACKGROUND_SCRUB_DATA_UNCOMPRESSED OFF 24# 25# show that it's writable 26# 27set global innodb_background_scrub_data_uncompressed=ON; 28select @@global.innodb_background_scrub_data_uncompressed; 29@@global.innodb_background_scrub_data_uncompressed 301 31set global innodb_background_scrub_data_uncompressed=OFF; 32select @@global.innodb_background_scrub_data_uncompressed; 33@@global.innodb_background_scrub_data_uncompressed 340 35set global innodb_background_scrub_data_uncompressed=1; 36select @@global.innodb_background_scrub_data_uncompressed; 37@@global.innodb_background_scrub_data_uncompressed 381 39set session innodb_background_scrub_data_uncompressed=1; 40ERROR HY000: Variable 'innodb_background_scrub_data_uncompressed' is a GLOBAL variable and should be set with SET GLOBAL 41# 42# incorrect types 43# 44set global innodb_background_scrub_data_uncompressed=1.1; 45ERROR 42000: Incorrect argument type to variable 'innodb_background_scrub_data_uncompressed' 46set global innodb_background_scrub_data_uncompressed=1e1; 47ERROR 42000: Incorrect argument type to variable 'innodb_background_scrub_data_uncompressed' 48set global innodb_background_scrub_data_uncompressed="foo"; 49ERROR 42000: Variable 'innodb_background_scrub_data_uncompressed' can't be set to the value of 'foo' 50SET @@global.innodb_background_scrub_data_uncompressed = @start_global_value; 51